Viral and Bacterial Infections of the Skin

Project in Microbiology and Parasitology

BACTERIAL INFECTIONS OF THE SKIN

• • • • • • • • • • • • •

Cellulitis Folliculitis Furunculosis (Boils) Erysipelas Hidradenitis Suppurativa Rocky Mountain Spotted Fever Impetigo Staphylococcal Scalded Skin Syndrome Toxic Shock Syndrome Narcotizing Fasciitis Pitted Keratolysis Trichomycosis Axilliaris Erythrasma

Cellulitis Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters, burns, insect bites, surgical wounds, or sites of intravenous catheter insertion. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body. The mainstay of therapy remains treatment with appropriate antibiotics.

Causes Cellulitis is caused by a type of bacteria entering the skin, usually by way of a cut, abrasion or break in the skin. This break does not need to be visible. Group A Streptococcus and Staphylococcus are the most common of these bacteria, which are part of the normal flora of the skin but cause no actual infection while on the skin's outer surface. Predisposing conditions for cellulitis include insect bite, blistering, animal bite, tattoos, pruritic skin rash, recent surgery, athlete's foot, dry skin, eczema, injecting drugs (especially subcutaneous or intramuscular injection or where an attempted IV injection "misses" or blows the vein), pregnancy, diabetes and obesity, which can affect circulation, as well as burns and boils, though there is debate as to whether minor foot lesions contribute

Risk factors The elderly and those with immunodeficiency (a weakened immune system) are especially vulnerable to contracting cellulitis. Diabetics are more susceptible to cellulitis than the general population because of impairment of the immune system; they are especially prone to cellulitis in the feet because the disease causes impairment of blood circulation in the legs leading to diabetic foot/foot ulcers. Poor control of blood glucose levels allows bacteria to grow more rapidly in the affected tissue and facilitates rapid progression if the infection enters the bloodstream. Neural degeneration in diabetes means these ulcers may not be painful and thus often become infected.

Incubation Cellulitis can develop in as little as 24 hours or can take days to develop. Duration In many cases, cellulitis takes less than a week to disappear with antibiotic therapy.However, it can take months to resolve completely in more serious cases and can result in severe debility or even death if untreated. If it is not properly treated, it may appear to improve but can resurface months or even years later. Treatment Treatment consists of resting the affected limb or area, cleaning the wound site if present (with debridement of dead tissue if necessary) and treatment with oral antibiotics, except in severe cases, which may require admission and intravenous (IV) therapy. Flucloxacillin monotherapy (to cover staphylococcal infection) is often sufficient in mild cellulitis, but in more moderate cases or where streptococcal infection is suspected then usually combined with oral phenoxymethylpenicillin or intravenous benzylpenicillin, or ampicillin/amoxicillin (e.g. co-amoxiclv in the UK).

Pain relief is also often prescribed, but excessive pain should always be considered relevant, as it is a symptom of necrotising fasciitis, which requires emergency surgical attention. As in other maladies characterized by wounds or tissue destruction, hyperbaric oxygen treatment can be a valuable adjunctive therapy, but is not widely available. Prevention Any wound should be cleaned and dressed appropriately. Changing bandages daily or when they become wet or dirty will reduce the risk of contracting cellulitis. Medical advice should be sought for any wounds that are deep or dirty and when there is concern about retained foreign bodies

Folliculitis - is the inflammation of one or more hair follicles. The condition may occur anywhere on the skin. Folliculitis starts when hair follicles are damaged by friction from clothing, an insect bite, blockage of the follicle, shaving or too tight braids too close to the scalp traction folliculitis. In most cases of folliculitis, the damaged follicles are then infected with the bacteria Staphylococcus (staph).

Different Types of Folliculitis • Tinea barbae is similar to barber's itch, but the infection is caused by the fungus T. rubrum. • Malassezia folliculitis, formerly known as Pityrosporum folliculitis, is caused by malassezia yeast. • Pseudofolliculitis barbae is a disorder occurring primarily in men of African descent. If curly beard hairs are cut too short, they may curve back into the skin and cause inflammation. • Hot tub folliculitis is caused by the bacteria Pseudomonas aeruginosa often found in new hot tubs.The folliculitis usually occurs after sitting in a hot tub that was not properly cleaned before use. Symptoms are found around the body parts that sit in the hot tub -- typically the legs, hips, and buttocks and surrounding areas. Symptoms are typically amplified around regions that were covered by wet clothing, such as bathing suits.

• Sycosis vulgaris, Sycosis barbae or Barber's itch is a staphylococcus infection of the hair follicles in the bearded area of the face, usually the upper lip. Shaving aggravates the condition. • Eosinophilic folliculitis may appear in persons with impaired immunity (AIDS, blood disorders). • Herpetic folliculitis may occur when Herpes Simplex Virus infection spreads to nearby hair follicles - mostly around the mouth. It typically occurs in persons with AIDS. • Gram negative folliculitis may appear after prolonged acne treatment with antibiotics. • Folliculitis decalvans or tufted folliculitis usually affects scalp. Several hairs arise from the same hair follicle. Scarring and permanent hair loss may follow. The cause is unknown.

causes scars on the nape of the neck. It is most common among males of African descent with curly hair.

• Folliculitis keloidalis

• Oil folliculitis is inflammation of hair follicles due to exposure to various oils and typically occurs on forearms or thighs. It is common in refinery workers, road workers, mechanics, sheep shearers. Even makeup may cause it.

Symptoms • rash (reddened skin area) • pimples or pustules located around a hair follicle – may crust over – typically occur on neck, axilla, or groin area – may be present as genital lesions • itching skin • spreading from leg to arm to body through improper treatment of antibiotics

Treatment • Topical antiseptic treatment is adequate for most cases • Topical antibiotics such as mupirocin or neomycin containing ointment • Some patients may benefit from systemic narrow-spectrum penicillinase-resistant penicillins (such as dicloxacillin in US, or flucloxacillin in UK)

What increases my risk of developing folliculitis? • You are more likely to get folliculitis if you: • Use a hot tub, whirlpool, or swimming pool that is not properly treated with chlorine. • Wear tight clothes. • Use antibiotics or steroid cream for long periods. • Use or work with substances that can irritate or block the follicles. Examples include makeup, cocoa butter, motor oil, tar, and creosote. • Have an infected cut, scrape, or surgical incision. The bacteria or fungi can spread to nearby hair follicles. • Have a disease such as diabetes or HIV that lowers your ability to fight infection.

Boil (furuncle) Boil (or furuncle) is a skin disease caused by the infection of hair follicles, resulting in the localized accumulation of pus and dead tissue. Individual boils can cluster together and form an interconnected network of boils called carbuncles.

Causes • Furuncles are very common. Furuncles are generally caused by Staphylococcus aureus, but they may be caused by other bacteria or fungi found on the skin's surface. Damage to the hair follicle allows these bacteria to enter deeper into the tissues of the follicle and the subcutaneous tissue. • Furuncles may occur in the hair follicles anywhere on the body, but they are most common on the face, neck, armpit, buttocks, and thighs. Furuncles can be single or multiple.

Symptoms Boils are red, pus-filled lumps that are tender, warm, and extremely painful. A yellow or white point at the center of the lump can be seen when the boil is ready to drain or discharge pus. An abscess is also a contained collection of pus; however, it can occur anywhere in or on the body. A boil always involves a hair follicle.

Characteristics • • • • •

Is usually pea-sized, but may be as large as a golf ball May develop white or yellow centers (pustules) May join with another furuncle or spread to other skin areas May grow rapidly May weep, ooze, crust

Other symptoms may include: • Fatigue • Fever • General ill-feeling • Itching before furuncle develops • Skin redness or inflammation around the lesion

Treatment •

Furuncles may heal on their own after an initial period of itching and mild pain. More often, they increase in discomfort as pus collects. They finally burst, drain, and then heal on their own.

•

Furuncles usually must drain before they will heal. This most often occurs in less than 2 weeks. Treatment by a health care provider is needed if a furncle lasts longer than 2 weeks, returns, is located on the spine or the middle of the face, or occurs with a fever or other symptoms because the infection may spread and cause complications.

•

Warm moist compresses encourage furuncles to drain, which speeds healing. Gently soak the area with a warm, moist cloth several times each day. Deep or large lesions may need to be drained surgically by a health care provider. Never squeeze a boil or attempt to cut it open it at home because this can spread the infection and make it worse.

• Meticulous hygiene is important to prevent the spread of infection. Draining lesions should be cleaned frequently. You should wash your hands very well The after touching a furuncle. Do not re-use or share washcloths or towels. Clothing, washcloths, towels, and sheets or other items that contact infected areas should be washed in very hot (preferably boiling) water. Dressings should be changed frequently and discarded in a manner that contains the drainage, such as by placing them in a bag that can be closed tightly before discarding. • Antibacterial soaps and topical antibiotics are of little benefit once a furuncle has formed. Systemic antibiotics may help to control infection in those with repeateda furuncles.

• • • • • • • • •

Possible Complications Abscess of the skin, spinal cord, brain, kidneys, or other organ Brain infection Endocarditis Osteomyelitis Permanent scarring Sepsis Spinal cord infection Spread of infection to other parts of the body or skin surfaces

Erysipelas It is an acute streptococcus bacterial infection of the dermis, resulting in inflammation.

Causes Most cases of erysipelas are due to Streptococcus pyogenes (also known as beta-hemolytic group A streptococci), although non-group A streptococci can also be the causative agent. Historically, the face was most affected; today the legs are affected most often. Erysipelas infections can enter the skin through minor trauma, eczema, surgical incisions and ulcers, and often originate from strep bacteria in the subject's own nasal passages

Signs and symptoms Erysipelas on an arm Patients typically develop symptoms including high fevers, shaking, chills, fatigue, headaches, vomiting, and general illness within 48 hours of the initial infection. The erythematous skin lesion enlarges rapidly and has a sharply demarcated raised edge. It appears as a red, swollen, warm, hardened and painful rash, similar in consistency to an orange peel. More severe infections can result in vesicles, bullae, and petechiae, with possible skin necrosis. Lymph nodes may be swollen, and lymphedema may occur. Occasionally, a red streak extending to the lymph node can be seen. The infection may occur on any part of the skin including the face, arms, fingers, legs and toes, but it tends to favor the extremities. Fat tissue is most susceptible to infection, and facial areas typically around the eyes, ears, and cheeks. Repeated infection of the extremities can lead to chronic swelling (lymphadenitis).

Risk factors This disease is most common among the elderly, infants, and children. People with immune deficiency, diabetes, alcoholism, skin ulceration, fungal infections and impaired lymphatic drainage (e.g., after mastectomy, pelvic surgery, bypass grafting) are also at increased risk.

Hidradenitis suppurativa It is a chronic skin inflammation marked by the presence of blackheads and one or more red, tender bumps (lesions). The lesions often enlarge, break open and drain pus. Scarring may result after several recurrences Considered a severe form of acne (acne inversa), hidradenitis suppurativa occurs deep in the skin around oil (sebaceous) glands and hair follicles. The parts of the body affected — the groin and armpits, for example — are also the main locations of apocrine sweat glands.

Signs and symptoms • Small pitted areas of skin containing blackheads, often appearing in pairs or a "double-barrel" pattern. • One or more red, tender bumps (lesions) that fill with pus. The bumps often enlarge, break open and drain pus. The drainage may have an unpleasant odor. Itching, burning and excessive sweating may accompany the bumps. • Painful, pea-sized lumps that grow under the skin. These hard lumps, which may persist for years, can enlarge and become inflamed. • Painful bumps or sores that continually leak fluid. These open wounds heal very slowly, if at all, often leading to scarring and the development of tunnels under the skin.

Hidradenitis suppurativa often starts at puberty with a single, painful bump that persists for weeks or months. For some people, the disease progressively worsens and affects multiple areas of their body. Other people experience only mild symptoms. Excess weight, stress, hormonal changes, heat or excessive perspiration can worsen symptoms.

Causes Hidradenitis suppurativa occurs deep in the skin around oil (sebaceous) glands, apocrine sweat glands and hair follicles. The apocrine sweat glands release fluid, dead skin cells and other substances into the hair follicle. This mixes with the oil from the sebaceous gland. Hidradenitis suppurativa develops when the oil glands and hair follicle openings become blocked with these substances. When oils and other skin products become trapped, they push into surrounding tissue. Bacteria can then trigger infection and inflammation. It's not known why this blockage occurs, but a number of factors — including hormones, genetics, cigarette smoking and excess weight — may all play a role.

Rocky Mountain Spotted Fever It is the most lethal and most frequently reported rickettsial illness in the United States. It has been diagnosed throughout the Americas. Some synonyms for Rocky Mountain spotted fever in other countries include “tick typhus,” “Tobia fever” (Colombia), “São Paulo fever” or “febre maculosa” (Brazil), and “fiebre manchada” (Mexico). It is distinct from the viral tick-borne infection, Colorado tick fever.

Cause • The disease is caused by Rickettsia rickettsii a species of bacterium that is spread to humans by Dermacentor ticks. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment it can be fatal

Signs and symptoms Rocky Mountain spotted fever can be very difficult to diagnose in its early stages, even among experienced physicians who are familiar with the disease. People infected with R. rickettsii usually notice symptoms following an incubation period of one to two weeks after a tick bite. The early clinical presentation of Rocky Mountain spotted fever is nonspecific and may resemble a variety of other infectious and non-infectious diseases.

Initial symptoms may include: • • • • • •

fever nausea emesis severe headache muscle pain lack of appetite

Later signs and symptoms include: • • • •

maculopapular rash petechial rash abdominal pain joint pain

Treatment Appropriate antibiotic treatment is initiated immediately when there is a suspicion of Rocky Mountain spotted fever on the basis of clinical and epidemiological findings. Treatment should not be delayed until laboratory confirmation is obtained. In fact, failure to respond to a tetracycline antibiotic argues against a diagnosis of Rocky Mountain spotted fever. Severely ill patients may require longer periods before their fever resolves, especially if they have experienced damage to multiple organ systems. Preventive therapy in non-ill patients who have had recent tick bites is not recommended and may, in fact, only delay the onset of disease.

Doxycycline (For adults, 100 mg every 12 hours. For children under 45 kg [100 lb], 4 mg/kg body weight per day in two divided doses) is the drug of choice for patients with Rocky Mountain spotted fever. Therapy is continued for at least 3 days after fever subsides and until there is unequivocal evidence of clinical improvement, generally for a minimum total course of 5 to 10 days. Severe or complicated disease may require longer treatment courses. Doxycycline is also the preferred drug for patients with ehrlichiosis, another ticktransmitted infection with signs and symptoms that may resemble Rocky Mountain spotted fever.

Chloramphenicol is an alternative drug that can be used to treat Rocky Mountain spotted fever; however, this drug may be associated with a wide range of side effects and may require careful monitoring of blood levels (as it can cause aplastic anemia).

Impetigo This is a skin infection typically caused by one of two bacteria: group A streptococcus (the same bacteria that cause strep throat) or staphylococcus aureus. These fairly common bacteria are found on the skin of healthy people. When the skin is broken — like with a cut or a scratch — they can enter the open wound and cause impetigo. Someone whose skin becomes infected develops blisters that usually burst, ooze fluid, and then harden into a honey-colored crust.

• Impetigo can affect skin anywhere on the body but often attacks the area around the nose and mouth. It is more likely to show up on skin that is already irritated or raw from eczema, poison ivy, or an insect bite. • Touching the infected skin and then touching another part of the body can spread the infection to that spot. It also can be spread to someone else if another person touches the infected area. Because kids in preschool and elementary school have lots of close contact with other kids, impetigo occurs most commonly in them, but anyone can get it

Signs and Symptoms Tiny blisters are usually the first symptom of impetigo. The blisters can be caused by group A streptococcus or staphylococcus aureus. When the blisters burst, the skin underneath them is moist, red, and may ooze fluid. Next, a tan or yellow-brown crust covers the wet areas, making it look like they've been coated with honey or brown sugar. Staphylococcus aureus infection may also cause larger blisters filled with fluid that starts out clear but then becomes cloudy. These blisters usually remain whole without bursting for a longer time. It can be difficult to tell if a case of impetigo is caused by strep or staph bacteria. But the treatment is similar, no matter which type of bacteria caused the infection.

Prevention Good hygiene practices can help prevent impetigo from spreading. Those who are infected should use soap and water to clean their skin and take baths or showers regularly. Non-infected members of the household should pay special attention to areas of the skin that have been injured, such as cuts, scrapes, bug bites, areas of eczema, and rashes. These areas should be kept clean and covered to prevent infection. In addition, anyone with impetigo should cover the impetigo sores with gauze and tape. All members of the household should wash their hands thoroughly with soap on a regular basis. It is also a good idea for everyone to keep their fingernails cut short to make hand washing more effective. Contact with the infected person and his or her belongings should be avoided, and the infected person should use separate towels for bathing and hand washing. If necessary, paper towels can be used in place of cloth towels for hand drying. The infected person's bed linens, towels, and clothing should be separated from those of other family members, as well. Whilst suffering from impetigo, it is best to stay indoors for a few days to stop any bacteria from getting into the blisters and making the infections worse. When a person has impetigo, it is common for him/her to get it a second time in the space of 6–9 months. This usually occurs in persons aged 12–16.a

Treatment For generations, the disease was treated with an application of the antiseptic gentian violet. Today, topical or oral antibiotics are usually prescribed. Treatment may involve washing with soap and water and letting the impetigo dry in the air. Mild cases may be treated with bactericidal ointment, such as fusidic acid, mupirocin, chloramphenicol or neosporin, which in some countries may be available over-the-counter. More severe cases require oral antibiotics, such as dicloxacillin, flucloxacillin or erythromycin. Alternatively amoxicillin combined with clavulanate potassium, cephalosporins (1st generation) and many others may also be used as an antibiotic treatment

Staphylococcal Scalded Skin Syndrome It is an illness characterized by red blistering skin that looks like a burn or scald, hence its name staphylococcal scalded skin syndrome. SSSS is caused by the release of two exotoxins (epidermolytic toxins A and B) from toxigenic strains of the bacteria Staphylococcus aureus. Desmosomes are the part of the skin cell responsible for adhering to the adjacent skin cell. The toxins bind to a molecule within the desmosome called Desmoglein 1 and break it up so the skin cells become unstuck. SSSS has also been called Ritter's disease or Lyell's disease when it appears in newborns or young infants.

Signs and Symptoms SSSS usually starts with fever, irritability and widespread redness of the skin. Within 24-48 hours fluid-filled blisters form. These rupture easily, leaving an area that looks like a burn. Characteristics of the rash include: • Tissue paper-like wrinkling of the skin is followed by the appearance of large fluid-filled blisters (bullae) in the armpits, groin and body orifices such as the nose and ears. • Rash spreads to other parts of the body including the arms, legs and trunk. In newborns, lesions are often found in the diaper area or around the umbilical cord. • Top layer of skin begins peeling off in sheets, leaving exposed a moist, red and tender area. • Other symptoms may include tender and painful areas around the infection site, weakness, and dehydration.

Risk Factors SSSS occurs mostly in children younger than 5 years, particularly neonates (newborn babies). Lifelong protective antibodies against staphylococcal exotoxins are usually acquired during childhood which makes SSSS much less common in older children and adults. Lack of specific immunity to the toxins and an immature renal clearance system (toxins are primarily cleared from the body through the kidneys) make neonates the most at risk. Immunocompromised individuals and individuals with renal failure, regardless of age, may also be at risk of SSSS.

Treatment Treatment usually requires hospitalization, as intravenous antibiotics are generally necessary to eradicate the staphylococcal infection. A penicillinase-resistant, antistaphylococcal antibiotic such as flucloxacillin is used. Depending on response to treatment, oral antibiotics can be substituted within several days. The patient may be discharged from hospital to continue treatment at home. Other supportive treatments include:  Paracetamol when necessary for fever and pain.  Maintaining fluid and electrolyte intake.  Skin care (the skin is often very fragile)  Although the outward signs of SSSS look bad, children generally recover well and healing is usually complete within 5-7 days of starting treatment.

Complications • SSSS usually follows a benign course when diagnosed and treated appropriately. However, if left untreated or treatment is unsuccessful, severe infections such as sepsis, cellulitis, and pneumonia may develop. Death can follow severe infection.

Toxic shock syndrome It is an uncommon but severe acute illness with fever, widespread red rash accompanied by involvement of other body organs. Toxic shock syndrome is a medical emergency that requires prompt treatment. Toxic shock syndrome featured in general public news in the early 1980s when an epidemic occurred. It was linked to the prolonged use of highly absorbent tampons in menstruating women. Since then manufacturers have made changes to tampon production and the number of cases of tampon-induced toxic shock syndrome has dropped significantly. Other causes for toxic shock syndrome include the use of contraceptive diaphragms and vaginal sponges (by women), as well as wound infections.

Causes Toxic shock syndrome is caused by the release of exotoxins from toxigenic strains of the bacteria Staphylococcus aureus and Streptococcus pyogenes. Toxin-producing strains of Staphylococcus aureus causing toxic shock syndrome was first formally described in 1978. Prior to this time the syndrome was known as staphylococcal scarlet fever. Both menstrual and nonmenstrual forms of toxic shock syndrome are caused by these toxins, which release massive amounts of cytokines (cellmediator chemicals) that produce fever, rash, low blood pressure, tissue injury and shock. Strains of Staphylococcus aureus, producing toxic shock syndrome toxin-1 (TSST-1), cause almost all of the cases of menstrual toxic shock syndrome. Non-menstrual toxic shock syndrome are caused by strains producing either TSST-1 or staphylococcal enterotoxin B or C.

Signs and Symptoms Toxic shock syndrome and STSS share similar signs and symptoms. Fever, rash, low blood pressure, and multiple organ involvement are seen as the hallmarks of these diseases. Shedding of the skin in large sheets, especially of the palms and soles, is usually seen 1-2 weeks after the onset of illness. Individuals may experience symptoms and signs differently.

Narcotizing fasciitis Necrotizing fasciitis is a very serious bacterial infection of the soft tissue and fascia (a sheath of tissue covering the muscle). The bacteria multiply and release toxins and enzymes that result in thrombosis (clotting) in the blood vessels. The result is destruction of the soft tissues and fascia.

There are three main types of necrotising fasciitis: • Type I (polymicrobial i.e. more than one bacteria involved) • Type II (due to haemolytic group A streptococcus) • Type III (gas gangrene

Bacteria causing type 1 necrotising fasciitis include Staphylococcus aureus, Haemophilus, Vibrio and several other aerobic and anaerobic strains. It usually follows significant injury or surgery. Type II necrotizing fasciitis has recently been sensationalized in the media and is commonly referred to as flesh-eating disease. Type III is caused by Clostridia perfringens or less commonly Clostridia septicum. It usually follows significant injury or surgery and results in gas under the skin: this makes a crackling sound called crepitus.

Signs and symptoms • Symptoms appearing usually within 24 hours of a minor injury: • Pain in the general area of the injury and worsening over time • Flu-like symptoms such as nausea, fever, diarrhea, dizziness and general malaise • Intense thirst as body becomes dehydrated

• Within 3-4 days of the initial symptoms the following may occur: • Affected area starts to swell and may show a purplish rash • Large dark marks form that turn into blisters filled with dark fluid • Wound starts to die and area becomes blackened (necrosis) • Severe pain • By about days 4-5, the patient is very ill with dangerously low blood pressure and high temperature. The infection has spread into the bloodstream and the body goes into toxic shock. The patient may have altered levels of consciousness or become totally unconscious.

Trichomycosis axillaris

Trichomycosis axillaris is a relatively common superficial bacterial colonization of the axillary hair shafts. Granular concretions, which are yellow, black, or red, adhere to the hair shaft and clinically characterize this condition.

Cause It is caused by the overgrowth of Corynebacterium (mostly Corynebacterium tenuis) and basically the concretions consist of tightly packed bacteria. They prefer moist areas of the body thus mainly affect underarm hair, and to a lesser extent, pubic hair (trichomycosis pubis). Trichomycosis axillaris occurs in males and females of all races from both temperate and tropical climates. It appears to be more common in men than women but this is because many women shave their underarm hair.

Signs and Symptoms Usually the condition is symptomless and all that is noticed is sweaty smelly armpits. On closer inspection, 1-2 mm yellow, red or black concretions can be found encircling the hair shaft, making the hair appear beaded or thicker. Sweat may be coloured according to the colour of the concretions and may stain clothing. Yellow concretions are the most common, whilst red and black are seen most often in tropical climates. Rarely, bacteria may invade and destroy the hair shaft.

Pitted Keratolysis Pitted keratolysis is a skin infection that can be caused by wearing tight or restricting footwear and excessive sweating during exercise. The infection is characterized by craterlike pits on the surface of the feet and toes, particularly weight bearing areas. Treatment consists of the application of topical antibiotics. After discontinuation of the antibotical creme, be sure to change socks frequently. After exercise be sure to thoroughly clean your feet. Dry after cleaning so they do not remain warm and moist. Pitted Keratolysis is caused by bacteria, which thrive in these environments.

Causes • Cutaneous infection with Micrococcus sedentarius. • Dermatophilus congolensis.. • Actinomyces. • K sedentarius. • Staphylococcus epidermidis

Sign and Symptoms • • • •

Sole of the forefoot . Small punched-out circular lesions. Peeling, cracking, and scaling of the feet. Redness, blisters, or softening and breaking down (maceration) of the skin. • Itching, burning, or both.

Treatment • Pitted keratolysis can be successfully treated with topical antibiotics such as fusidic acid cream, or with oral erythromycin . • Wear boots for as short a period as possible • Wash feet with soap or antiseptic cleanser twice daily • Apply antiperspirant to the feet at least twice weekly • Do not wear the same shoes two days in a row – dry them out • Do not share footwear or towels with others. • Limit the use of occlusive footwear and reduce foot friction with properly fitting footwear. • Absorbent cotton socks must be changed frequently to prevent excessive foot moisture. • Wool socks tend to whisk moisture away from the skin and may be helpful.

Erythrasma It is a chronic superficial localized skin infection caused by bacteria called Corynebacterium minutissimum. Erythrasma is more common in warm, humid climates, or in individuals with poor hygiene, increased sweating, obesity, diabetes, advanced age and poor immune function. It is more commonly located in intertrigineous areas or skin folds including the groin, armpit, intergluteal fold, inframammary, and periumbilical areas.

Signs and Symptoms The symptoms of Erythrasma are mainly visual. The patches created by the disease are of pinkish to red color. They later become tanned in appearance. The affected skin is visibly discolored from the normal skin. People who have diabetes can develop the patches caused by Erythrasma in less likely areas like arms, trunk and legs. The areas affected by the patches assume a wrinkled texture. Generally these discolored skin patches do not cause pain, but some patients complain about itchiness. Particularly the patches in one’s groin areas can cause some uneasiness. Sometimes, this disease can be confused with similar other dermatological disorders like the fungal contaminations and ringworm. Therefore, Wood's lamp is employed in detecting cases of Erythrasma. This UV light makes the lesions emit a deep red aura.

Treatment of Erythrasma In most cases of Erythrasma, oral and topical antibiotics are prescribed by the doctors to combat the infections. Antibacterial soaps can also be used to treat these cases. It prevents the infection from reappearing in the patient’s body. If a person suspects that he has contracted the ailment he should wash the area with antiseptic solutions and try to keep it dry. There are some skin creams available in the market like miconazole and tolnaftate. These can be applied to fight the infection.

If self medication does not bring any positive result to a patient, he must take medical guidance. The doctors usually recommend topical antibiotic solutions like clindamycin and erythromycin. Another widely used medicine that the physicians favor is Whitfield's ointment. This is basically an amalgam of salicylic acid and benzoic acid. Since the infection occurs in the moist body parts, aluminum chloride solution is often prescribed to prevent perspiration and moisture formation.

Measles It is an infection of the respiratory system caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. Morbilliviruses, like other paramyxoviruses, are enveloped, singlestranded, negative-sense RNA viruses. Symptoms include fever, cough, runny nose, red eyes and a generalized, maculopapular, erythematous rash. Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious—90% of people without immunity sharing a house with an infected person will catch it. The infection has an average incubation period of 14 days (range 6–19 days) and infectivity lasts from 2–4 days prior, until 2–5 days following the onset of the rash (i.e. 4-9 days infectivity in total).

• An alternative name for measles in Englishspeaking countries is rubeola, which is sometimes confused with rubella (German measles); the diseases are unrelated. In some other European languages, rubella and rubeola are synonyms, and rubeola is not an alternative name for measles.

Signs and Symptoms Measles appears as distinct clinical stages.

Incubation period • Ranges from 7-14 days (average 10-11 days). • Patient usually have no symptoms. • Some may experience symptoms of primary viral spread (fever, spotty rash and respiratory symptoms due to virus in the blood stream) within 2-3 days of exposure.

Prodrome • Generally occurs around 10-12 days from exposure. • Appears as fever, malaise and loss of appetite, followed by conjunctivitis (red eyes), cough and coryza (blocked or runny nose).

• 2-3 days into the prodrome phase, Koplik spots appear. These are blue-white spots on the inside of the mouth and occur 24-48 hours before the exanthem (rash) stage. • Symptoms usually last for 2-5 days but in some cases may persist for as long as 7-10 days.

Exanthem (rash) • Red spots ranging from 0.1-1.0cm in diameter appear on the 4th or 5th day following the start of symptoms. • This non-itchy rash begins on face and behind the ears. Within 24-36 hours it spreads to the entire trunk and extremities (palms and soles rarely involved). • The spots may all join together, especially in areas of the face. • Rash usually coincides with the appearance of a high fever >/=40degC. • Rash begins to fade 3-4 days after it first appears. To begin with it fades to a purplish hue and then to brown/coppery coloured lesions with fine scales.

Recovery • Cough may persist for 1-3 weeks. • Measles-associated complications may be the cause of persisting fever beyond the 3rd day of the rash

Treatment

• • • • •

There is no specific treatment for measles which is why immunisation is so important. Treatment for mild cases of measles is supportive. Give paracetamol for fever Maintain fluid intake so dehydration doesn't occur Provide nutritional support if necessary Observe high-risk individuals carefully to prevent complications Severe cases of measles usually require hospitalisation. Antibiotics may be given to treat secondary bacterial infections from complications such as otitis media, infectious diarrhoea, pneumonia and sepsis.

Complications Approximately 30% of reported measles cases have one or more complications. The most common complications that occur are: • Diarrhoea that may be fatal if dehydration occurs • Otitis media (almost exclusively in children) which may lead to deafness • Pneumonia (either primary viral or secondary bacterial). This is the most common cause of death.

Prevention Measles can be prevented by vaccination with live attenuated measles vaccine. It is available as a single antigen preparation or combined with live attenuated mumps or rubella vaccines, or both. Combined measles, mumps and rubella (MMR) vaccine is currently part of routine immunisation programmes in most industrialised countries, including New Zealand. Measles vaccine induces long-term (probably life-long) immunity in most individuals. Vaccination schedules recommend a twodose immunisation strategy, the first dose at 12-15 months, followed by a second dose at 4-6 years. Individuals vaccinated prior to 1968 may require revaccination as vaccines used before this time may not have conferred life-long immunity.

Rubella Rubella, also known as German measles is a viral disease characterized by rash, swollen glands and fever. The disease is usually mild and of little significance unless you are pregnant. Infection of a pregnant woman (congenital rubella syndrome) commonly results in miscarriage, stillbirth, or birth of an infant with major birth abnormalities.

Signs and Symptoms • Slight fever, sore throat, runny nose and malaise (may occur prior to appearance of rash, more so in adults than in children). • Rash begins on the face that spreads to the neck, trunk and extremities. – Appear as pink or light red spots about 2-3mm in size. – Lasts up to 5 days (average is 3 days). – May or may not be itchy. – As rash passes, affected skin may shed in flakes. – Usually not as widespread as in measles. • Tender or swollen glands almost always accompany rubella, most commonly behind the ears and at the back of the neck.

Treatment Treatment for rubella focuses on caring for the specific symptoms, such as getting plenty of rest and drinking extra fluids so you do not get dehydrated. Acetaminophen, such as Tylenol, can be given to children and adults for fever. Do not give aspirin to anyone younger than 20 because of the possible link between aspirin and Reye syndrome. A baby (fetus) can get infected from a mother who has rubella during her pregnancy. Babies infected in the first trimester may also develop birth defects. Treatment varies according to the specific problem.

Chickenpox Chickenpox is a common illness among kids, particularly those under age 12. An itchy rash of spots that look like blisters can appear all over the body and may be accompanied by flu-like symptoms. Symptoms usually go away without treatment, but because the infection is very contagious, an infected child should stay home and rest until the symptoms are gone.

Chickenpox is caused by the varicella-zoster virus (VZV). Kids can be protected from VZV by getting the chickenpox (varicella) vaccine, usually between the ages of 12 to 15 months. In 2006, the Centers for Disease Control and Prevention (CDC) recommended a booster shot at 4 to 6 years old for further protection. The CDC also recommends that people 13 years of age and older who have never had chickenpox or received chickenpox vaccine get two doses of the vaccine at least 28 days apart. A person usually has only one episode of chickenpox, but VZV can lie dormant within the body and cause a different type of skin eruption later in life called shingles (or herpes zoster). Getting the chickenpox vaccine significantly lowers your child's chances of getting chickenpox, but he or she may still develop shingles later.

Signs and Symptoms In children, chickenpox usually begins as an itchy rash of red papules (small bumps) progressing to vesicles (blisters) on the stomach, back and face, and then spreading to other parts of the body. The spread pattern can vary from person to person. Also, depending on the individual case, there may be only a scattering of vesicles or the entire body may be covered with between 250 to 500 vesicles. The vesicles tend to be very itchy and uncomfortable. Some children may also experience additional symptoms such as high fever, headache, coldlike symptoms and vomiting and diarrhea. Most adults who get chickenpox experience prodromal symptoms for up to 48 hours before breaking out in rash. These include fever, malaise, headache, loss of appetite and abdominal pain. The condition is usually more severe in adults and can be life-threatening in complicated cases.

Treatment • Trimming children's fingernails to minimize scratching. • Paracetamol to reduce fever and pain (do not use aspirin in children as this is associated with Reye's syndrome). • Calamine lotion and/or oral antihistamines to relieve itching. • Consider oral aciclovir (antiviral agent) in people older than 12 years who may be at increased risk of severe varicella infections.

Complications • Secondary bacterial infection of skin lesions caused from scratching • Dehydration from vomiting and diarrhea • Exacerbation of asthma • Viral pneumonia

Prevention A person with chickenpox is contagious 1-2 days before the rash appears and until all the blisters have formed scabs. This may take between 5-10 days. Children should stay away from school or childcare facilities throughout this contagious period. Adults with chickenpox who work amongst children, should also remain home.

Fifth Disease Fifth disease is a mild illness caused by a virus known as human parvovirus B19. The medical name for fifth disease is erythema infectiosum (EI). It is seen primarily in school-aged children between 5 and 14 years of age during the spring and winter. Fifth disease causes a reddish rash on the child's face so that it looks as if the child has been slapped on both cheeks

Signs and Symptoms • The first sign of fifth disease is firm red cheeks, which feel burning hot. A rash follows 1 to 4 days later with a lace or network pattern on the limbs and then the trunk. • The child with fifth disease is usually otherwise quite well, but may have a slight fever and headache. • Although most prominent in the first few days, the rash can persist at least intermittently for up to six weeks.

Treatment Fifth disease is not generally a serious condition. There is no specific treatment. Affected children may remain at school as the infectious stage occurs before the rash is evident The application of an ice-cold flannel can relieve the discomfort of burning hot cheeks.

Complications • Rarely fifth disease results in complications. • Arthritis in infected adults • Aplastic crisis in patients with blood disorders (potentially dangerous low blood cell count) • Intrauterine death (9%) or hydrops fetalis in 3% of the offspring of infected pregnant women can occur if the infection occurs in the first half of pregnancy. However, congenital malformations do not occur. As the risk of an adverse outcome is very low, the infection is not routinely screened for in pregnancy.

Roseola Roseola is caused by human herpesvirus 6 (HHV-6) and, less commonly, HHV-7 or other viruses. You may have also heard it called roseola infantum, exanthem subitum, or sixth disease. The name "sixth disease" simply comes from the fact that it was the sixth of the common children's diseases that cause rashes to be listed in a particular classification scheme. The other five are measles, scarlet fever, rubella, a variant of scarlet fever that is no longer recognized, and fifth disease

Signs and Symptoms • High fever (often up to 40 degC) for 3-5 days • Upper respiratory symptoms such as sore throat, cough, runny nose or congestion • Irritability and tiredness • Rash appears around days 3 to 5 as fever subsides – Typically small pink or red raised spots (2-5 mm in diameter) that blanch (turn white) when touched – Some spots may be surrounded by a lighter halo of pale skin – Starts on trunk and may spread to involve the neck, face, arms and legs – Non-itchy, painless and does not blister – May fade within a few hours or persist for as long as 2-3 days

Treatment There is no specific treatment for roseola. The disease is usually mild and self-limiting. Rest, maintaining fluid intake and paracetamol for fever is all that is usually required. Lukewarm baths or sponges can also be used to help reduce fever. No treatment is necessary for the rash as it does not itch or hurt and fades spontaneously.

Complications • Loss of consciousness • Jerking or twitching movements in the arms, legs or face for 2 to 3 minutes • Wet or soiled pants in an unconscious, toilet-trained child • Irritability

Infectious Mononucleosis Infectious mononucleosis is also known as ‘glandular fever’. It typically affects young adults aged 15 to 25 years. Infectious mononucleosis is caused by Human herpes virus type 4, more often known as Epstein Barr virus (EBV). This virus is passed from person to person by saliva such as sharing a glass or kissing. The incubation period from contact until symptoms is 1 to 2 months.

Clinical Features of Infectious Mononucleosis

Organ involved

Symptoms & signs

Spleen

•

Joints

•

Kidneys

•

Nervous system

•

Splenomegaly (an enlarged spleen) Arthritis in one or more joints Glomerulonephritis

•

Meningoencephalitis Bell's palsy (facial palsy) Transverse myelitis Guillain-Barré syndrome

Gastrointestinal tract

•

Hepatitis

Lungs

•

Interstitial pneumonia

Heart

•

Pericarditis

• •

Eyes

• • • • •

Blood system

•

•

•

•

•

Eyelid swelling Keratitis Uveitis Conjunctivitis Retinitis Autoimmune haemolytic anaemia (breakdown of red cells) Thrombocytopaenia (reduced platelet count) Neutropaenia (reduced white cell count) Cold agglutinins (proteins that precipitate in cooler conditions) Immunodeficiency

Involvement of the skin

• • • • •

Involvement of the skin is seen in about 10% of nonhospitalised patients. Most commonly, there is a faint, widespread, non-itchy rash, which lasts for about a week. It is described as maculopapular exanthem, i.e. there are flat patches that may contain small bumpy red spots. It thought to be directly due to the virus. This rash often appears on the trunk and upper arms first, and a few days later extends to involve the face and forearms. Other appearances of this rash include: Morbilliform (small, flat, measles-like patches) Papular (small bumps) Scarlatiniform (tiny spots like scarlet fever) Vesicular (little blisters) Purpuric (bruise-like)

Pityriasis Roseola It is a rash of unknown cause which lasts about six weeks. Pityriasis rosea most often affects teenagers or young adults. In most cases there are no other symptoms, but in some cases the rash follows a few days after a upper respiratory viral infection.

Pityriasis rosea may be set off by a viral infection but it does not appear to be contagious. Herpes viruses 6 and 7 have sometimes been associated with pityriasis rosea, and the rash may be a reactive response to these or other viruses. Pityriasis rosea clears up by itself in about six to twelve weeks. When clear, the skin returns to its normal appearance. It leaves no scars, although pale marks or brown discolouration may persist for a few months in dark skinned people.

Signs and Symptoms Pityriasis rosea symptoms include:  Initial phase. Pityriasis rosea typically begins with a large, slightly raised, scaly patch — called the herald patch — on your back, chest or abdomen.  Progression. Smaller fine, scaly spots usually appear across your back, chest or abdomen in a pine-tree pattern a few days to a few weeks after the herald patch. Rarely, smaller spots may also appear on your arms, legs or face. The rash may itch.  Color. The rash of pityriasis rosea often is scaly and pink, but if you have darker skin, it may be gray, dark brown or even black.  Other signs and symptoms. About half the people who develop pityriasis rosea have signs or symptoms of an upper respiratory infection — such as a stuffy nose, sore throat, cough or congestion — just before the herald patch appears

Causes • Pityriasis rosea may be set off by a viral infection but it does not appear to be contagious. Herpes viruses 6 and 7 have sometimes been associated with pityriasis rosea, and the rash may be a reactive response to these or other viruses. • Pityriasis rosea clears up by itself in about six to twelve weeks. When clear, the skin returns to its normal appearance. It leaves no scars, although pale marks or brown discolouration may persist for a few months in dark skinned people.

Treatment • General advice. The rash is irritated by soap; bathe or shower with plain water and bath oil, aqueous cream, or other soap substitute. Apply moisturizing creams to dry skin. • If the rash itches, treatment with a steroid cream or ointment usually brings prompt relief. The steroid probably does not speed up clearance of pityriasis rosea but it reduces the discomfort. • Extensive or persistent cases can be treated by phototherapy (ultraviolet light, UVB). • New information suggests early treatment with aciclovir may speed up recovery of at least some cases of pityriasis rosea.

Hand foot and mouth disease • Hand foot and mouth disease is a common mild and shortlasting condition most often affecting young children during the summer months. • Hand-foot-and-mouth is due to an enterovirus infection, usually Coxsackie virus A16, although it can also be due to Enterovirus 71. It is very infectious, so several members of the family or a school class may be affected. • After an incubation period of 3 to 5 days, the infection results in flat small blisters on the hands and feet, and oral ulcers. These are sometimes painful, so the child eats little and frets. There may be a mild fever. Sometimes in young children there is a rash on the buttocks.

Treatment Specific treatment is not necessary. Antiseptic mouth washes and simple analgesics such as paracetamol relieve the discomfort of eating.

Laterothoracic Exanthem Laterothoracic exanthem is also known as Asymmetric Periflexural Exanthem of Childhood (APEC). It is an uncommon rash affecting young children, which is suspected to be due to a viral infection.

Signs and Symptoms • Laterothoracic exanthem mainly occurs in winter and spring and affects twice as many girls as boys. The average age is two, most cases being between one and five years old. • The rash is often mistaken for eczema (dermatitis) or a fungal infection (ringworm). It usually starts in the armpit or groin and gradually extends outwards, remaining predominantly on one side of the body. It may spread to the face, genitalia, hands or feet. • The rash starts as tiny raised pink spots, which may be surrounded by a pale halo, then slowly becomes flat and scaly. The middle of older patches fades to a dusky grey. Occasionally the patches are net-like or in rings. Little blisters or blood spots may occur. The rash is usually quite itchy. • Sometimes other features of viral infection occur at the onset of the rash, such as a fever, sore throat, cold, vomiting and/or diarrhoea. The lymph glands in the armpits and groins may be enlarged.

Treatment • The rash will clear without treatment. The itching can be relieved with: • Emollients • Topical steroids • Oral antihistamines

Smallpox Smallpox is a highly contagious and sometimes deadly disease that is caused by infection with the variola virus. It has been around for thousands of years and has been associated with many deadly epidemics. Widespread vaccination between 1940 and 1970 has led to the global eradication of the virus and in 1980 the World Health Organization (WHO) officially declared smallpox eradicated. The last naturally occurring case of smallpox was in Somalia in 1977. The only remaining known variola virus isolates are stored at the Centers for Disease Control and Prevention (CDC) in the US and at the Vektor Institute in Russia. Renewed interest in smallpox is taking place, as there is concern that the variola virus may be used as an agent of bioterrorism. There are 2 clinical types of smallpox, variola major and variola minor. Variola major is the most common and severe form and has a death rate of about 30%. Variola minor is a much less common form with an estimated death rate of less than 1%.

Signs and Symptoms •

• • • • • • • • • •

• • •

Infection with the variola virus begins with an incubation period that can be from 7-17 days (on average 12-14 days). During this time most people experience no symptoms whatsoever and they are not contagious. The first sign of smallpox disease is the prodromal phase, which lasts 2-4 days and is characterised by: Fever (>40degC) Severe headache Nausea and vomiting Aching body Sore throat Small red spots occur on the tongue and in the mouth which turn into sores containing the virus Rash spreads to face, arms, legs, hands and feet and to all parts of the body within 24 hours (coincides with subsiding fever) Rash becomes raised bumps that then become fluid-filled with a depression in the centre (umbilicated) Fever recurs and stays high until scabs form The bumps turn into pustules that are raised, round and firm to touch. Pustules may reach between 4 and 6mm in diameter. After about 5 days pustules begin to form a crust and then scab. By about 3 weeks after the first signs of rash appearing, scabs fall off leaving marks on the skin that eventually become pitted scars. A person is contagious until all the scabs have fallen off. Smallpox could be confused with several other diseases, especially: Chickenpox (varicella), usually seen in children and affecting the trunk predominantly Widespread shingles (zoster) in immune compromised or elderly, normally starting in a single area of the body

Treatment • There is no cure for smallpox. The aim of keeping smallpox under control is to prevent it from occurring. If smallpox is suspected in an individual, state health officials must be notified immediately and containment of the virus a major priority. This would include strict respiratory and contact isolation for at least 17 days and vaccination of all contacts. • Treatment for an already ill smallpox patient should be supportive care consisting of adequate hydration and nutrition, eye care and antibiotics as needed for secondary skin infections. Vaccination within the incubation period, particularly if given within 3 days of exposure to the virus, has been shown to prevent or significantly lessen the severity of smallpox disease in most people.

Complications

• • • •

Most patients whom survive smallpox have extensive scarring of the skin. Other complications may include: Eye problems including corneal ulceration and blindness Bronchopneumonia Arthritis Osteomyelitis

Cowpox Cowpox is a viral skin infection caused by the cowpox or catpox virus. This is a member of the orthopoxvirus family, which includes the variola virus that causes smallpox. Cowpox is similar to but much milder than the highly contagious and sometimes deadly smallpox disease. Cowpox should also not be confused with cowpock, which is an alternative name for a condition called Milker’s nodules that is caused by a parapox virus.

Signs and Symptoms Most human cases of cowpox appear as one or a small number of pus-like lesions on the hands and face, which then ulcerate and form a black scab before healing on their own. This process can take up to 12 weeks with the following skin findings over that period: • • • • •

Days 1-6 (after infection): the site of infection appears as an inflamed macule (flat red lesion) Days 7-12: the inflamed lesion becomes raised (papular), then develops into a blister-like sore (vesicle) Days 13-20: the vesicle becomes filled with blood and pus and eventually ulcerates. Other lesions may develop close by. Weeks 3-6: the ulcerated wound turns into a deep-seated, hard, black crusty sore (eschar) which is surrounded by redness and swelling. Weeks 6-12: the eschar begins to flake and slough and the lesion heals, often leaving a scar behind. Other generalised symptoms patients may report are fever, tiredness, vomiting, and sore throat. Eye complaints such as conjunctivitis, periorbital swelling and corneal involvement have been reported. Enlarged painful local lymph nodes may also develop

Treatment • There is no cure for cowpox but the disease is self-limiting. The human immune response after being infected is sufficient to control the infections on its own. The lesions heal by themselves within 6-12 weeks. Often patients are left with scars at the site of the healed pox lesions. • Patients may feel unwell and require bed rest and supportive therapy. Wound dressings or bandages may be applied to lesions to prevent spread to other sites and potentially to other people. • Patients with underlying skin conditions such as atopic dermatitis may be at greater risk of generalised skin infections.

Chikungunya fever Chikungunya fever is a re-emerging viral illness that is spread from human-to-human by the bite of virus-carrying mosquitoes. The disease is mostly confined to people living in tropical Africa and Asia and is characterised by a sudden and severe fever, skin rash and joint and muscle pain.

Signs and Symptoms • Infection with the CHIK virus begins with a short incubation period of 2-4 days. At about 48 hours after being bitten by a virus-carrying mosquito, patients will experience sudden high fever with shaking chills. Some patients also get a maculopapular rash (red flat patches that may contain small raised spots) over the trunk, limbs and face. This tends to last 3 or 4 days. Commonly patients will experience severe myalgia (muscle pain) and arthralgia (joint pain). Joint pain initially starts in the small joints of the hands and feet, wrists and ankles, and later the larger joints. Other non-specific symptoms may include headache, slight photophobia and insomnia.

Treatment There is no vaccine or specific treatment available against CHIK V infection. Fortunately, the illness is usually selflimiting and resolves with time. Supportive therapy with antipyretics and nonsteroidal anti-inflammatory drugs (NSAIDs) are used to control fever and joint pain. Fever usually disappears after 2-3 days. Muscle and joint pain, which can be very severe usually lasts for about 5-7 days but in some cases may linger for much longer periods. Elderly patients in particular may suffer muscle and joint pain for several months. Skin discolouration and rash can be treated with sunscreens and topical corticosteroids. Skin rash on the face appears to resolve completely within about 3 weeks, whilst resolution is a little longer when other parts of the body are affected. Ulcers should be cleaned and treated with topical antimicrobials to prevent secondary infections. These usually heal within 7-10 days. More severe lesions may require systemic steroid treatment.

How to prevent chikungunya fever The best way to prevent chikungunya fever is by preventing spread of the virus by vector control. This means eliminating or controlling mosquito breeding sites. The CHIK V-carrying mosquito likes to breed in artificial containers and receptacles containing water. The following measures can be taken to reduce the breeding of mosquitoes. • • • • • •

• • • • •

Cover tightly with a lid all water tanks, cisterns, barrels, rubbish containers, etc. Remove or empty water in old tyres, tin cans, bottles, trays, etc. Check and clean out clogged gutters and flat roofs where water may have settled. Change water regularly in pet water dishes, birdbaths and plant trays. Introduce larvivorous fish (e.g. guppy) to ornamental water features as these eat the mosquito larvae. Trim weeds and tall grasses as adult mosquitoes seek these for shade on hot days. People can do the following to prevent themselves from being bitten by mosquitoes. Wear long sleeves and pants. Install secure screens to windows and doors to keep mosquitoes out. Use an insect repellent such as DEET. Sleep under mosquito curtains or nets, this is particularly important when children are sleeping or resting during daylight hours. In high-risk areas insecticide sprays may be used to kill mosquitoes.

Kaposi sarcoma Kaposi sarcoma is a disease of blood vessels that was considered very rare before the start of the AIDS pandemic. AIDS is due to infection with human immunodeficiency virus (HIV). There are four types of Kaposi sarcoma: • The classic type of Kaposi sarcoma affects elderly men of Mediterranean and Middle European descent and in men in Sub-Saharan Africa. • HIV-associated Kaposi sarcoma mainly affects men who have sex with men. • Endemic or African Kaposi sarcoma arises in some parts of Africa in children and young adults. • Iatrogenic Kaposi sarcoma is due to drug treatment causing immune suppression.

Signs and Symptoms Kaposi sarcoma presents as red to purplish spots (macules) and raised bumps (papules and nodules) anywhere on the skin or mucous membranes. Initially, the lesions are small and painless but they can ulcerate and become painful. There are various forms. • • • • • • • • • • • •

Localised nodular Locally aggressive Generalised lymphadenopathic Patch stage Localised plaques Exophytic lesions Infiltrative plaques Disseminated cutaneous and visceral disease Telangiectatic Keloidal Ecchymotic Lymphangioma-like / cavernous disease

Treatment • In HIV disease, if the lesions are not widespread or troublesome, often the best approach is simply to treat the underlying HIV infection with highly active antiretroviral drug combinations that suppress HIV replication (HAART). These drugs reduce the frequency of Kaposi sarcoma and may also prevent its progression or the development of new lesions. It is not yet clear why this approach works; one opinion is that the improvement in immune function results in reduced levels of tumour growth-promoting proteins. • Iatrogenic Kaposi sarcoma may improve or clear if it is possible to stop immune suppressive medication. • The choice of more specific treatment depends largely on the extent of the disease.

Treating localised lesions Small, localised lesions are generally only treated if theyare painful or they are causing cosmetic problems. It should be noted that lesions tend to recur after local treatments. Treatments include: • Cryotherapy with liquid nitrogen • Radiotherapy. This is most useful for classic Kaposi sarcoma and is less effective for HIV-associated disease. • Surgical excision of individual nodules. • Laser therapy, using pulsed dye laser or pulsed carbon dioxide laser. • Injection with anti-cancer drugs such as vinblastine • Topical application of alitretinoin gel (Panretin). This drug is not yet available in New Zealand.

Herpes simplex Herpes simplex is a common viral infection that presents with localised blistering. It affects most people on one or more occasions during their lives. There are two main types of herpes simplex virus (HSV), although there is considerable overlap. • Type 1, which is mainly associated with facial infections (cold sores or fever blisters) • Type 2, which is mainly genital (genital herpes)

Both type 1 and type 2 herpes simplex viruses reside in a latent state in the nerves which supply sensation to the skin. During an attack, the virus grows down the nerves and out into the skin or mucous membranes where it multiplies, causing the clinical lesion. After each attack it ‘dies back’ up the nerve fibre and enters the resting state again. First or primary attacks of Type 1 infections occur mainly in infants and young children, which are usually mild or subclinical. In crowded, underdeveloped areas of the world up to 100% of children have been infected by the age of 5. In higher socioeconomic groups the incidence is lower, for example less than half of university entrants in Britain have been infected. Type 2 infections occur mainly after puberty, often transmitted sexually. The initial infection more commonly causes symptoms.

• •

•

• • •

The infection can be passed on from someone else with an active infection and it can also be passed on from individuals without symptoms. The virus is shed in saliva and genital secretions, during a clinical attack and for some days or weeks afterwards. The amount shed from active lesions is 100 to 1000 times greater than when it is inactive. Spread is by direct contact with infected secretions. Minor injury helps inoculate the virus into the skin. The virus can be inoculated into any body site to cause a new infection, whether or not there has been a previous infection of either type. The source of the virus may be from elsewhere on the body especially in nail biters or thumb suckers. Herpes simplex can also be inoculated from external sources. Examples include: Nailfold infection in a health-care worker (‘herpetic whitlow’) Facial blisters in a rugby player (‘scrum pox’) Suckling infant with mouth sores

Treatment Mild uncomplicated eruptions of herpes simplex require no treatment. They may be covered if desired, e.g., with a hydrocolloid patch. As sun exposure often triggers facial herpes simplex, sun protection using high protection factor sunscreens and other measures is important. Severe infection may require treatment with an antiviral agent. Oral antiviral drugs include: • aciclovir • valaciclovir • famciclovir.

Complications Eye infection • Herpes simplex may cause swollen eyelids and conjunctivitis with opacity and superficial ulceration of the cornea (dendritic ulcer). The lymph gland in front of the ear is often enlarged and tender. Throat infection • Throat infections may be very painful. Eczema herpeticum • HSV in patients with atopic dermatitis or Darier disease may result in a severe rash known as eczema herpeticum. Numerous blisters and scabs erupt on the face or elsewhere, associated with swollen lymph glands and fever. Erythema multiforme • Recurrent erythema multiforme is an uncommon reaction to herpes simplex. Erythema multiforme mainly appears on the hands, forearms and lower legs and is characterised by target lesions, which sometimes blister. Nervous system • The nerves to the face may be infected by HSV, producing temporary paralysis of the affected muscles, sometimes with each attack. Rarely neuralgic pain may precede each recurrence of herpes by 1 or 2 days (Maurice's syndrome). Meningitis is rare. Widespread infection • This is more likely to arise in debilitated patients and may be serious

Shingles Shingles is a painful blistering rash caused by reactivation of varicella, the chickenpox virus. It is correctly known as herpes zoster. • Chickenpox or varicella is the primary infection with the virus, Herpes zoster, also called ‘varicella-zoster’. During this widespread infection, which usually occurs in childhood, virus is seeded to nerve cells in the spinal cord, usually of nerves that supply sensation to the skin. • The virus remains in a resting phase in these nerve cells for years before it is reactivated and grows down the nerves to the skin to produce shingles (zoster). This can occur in childhood but is much more common in adults, especially the elderly. • Shingles patients are infectious (resulting in chickenpox), both from virus in the lesions and in some instances the nose and throat.

Sign and Symptoms • The first sign of shingles is usually pain, which may be severe, in the areas of one or more sensory nerves, often where they emerge from the spine. The pain may be just in one spot or it may spread out. The patient usually feels quite unwell with fever and headache. The lymph nodes draining the affected area are often enlarged and tender. • Within one to three days of the onset of pain, a blistering rash appears in the painful area of skin. Sometimes, especially in children, shingles is painless. • It starts as a crop of closely-grouped red bumps in a continuous band on the area of skin supplied by one, occasionally two, and rarely more neighbouring spinal nerves. New lesions continue to appear for several days, each blistering or becoming pustular then crusting over. Shingles occasionally causes blisters inside the mouth or ears, and can also affect the genital area.

•

• •

•

The pain and general symptoms subside gradually as the eruption disappears. In uncomplicated cases recovery is complete in 2-3 weeks in children and young adults, and 3 to 4 weeks in older patients. Occasionally pain is not followed by the eruption - shingles "sine eruptione". These cases can be difficult to identify because there is no characteristic rash. The chest (thoracic), neck (cervical), forehead (ophthalmic) and lumbar/sacral sensory nerve supply regions are most commonly affected at all ages but the frequency of ophthalmic shingles increases with age. Rarely the eruption may affect both sides of the body. In elderly and undernourished patients the blisters are deeper. Healing may take many weeks and be followed by scarring. Muscle weakness arises in about one in twenty patients because the muscle nerves are affected as well as the sensory nerves. Facial nerve palsy is the most common result. There is a 50% chance of complete recovery and in time some improvement can be expected in nearly all cases.

Treatment

• • • •

•

If you think you may have shingles, see your doctor as soon as possible. Antiviral treatment can reduce pain and the duration of symptoms, but it is much less effective if started more than one to three days after the onset of the shingles. Rest and pain relief are important - try paracetamol initially A bland, protective application should be applied to the rash. Try povidone iodine or calamine lotion. Capsaicin cream may be helpful for pain relief for post-herpetic neuralgia. Oral antiviral medication is recommended in the following circumstances: – Facial shingles – Those with poor immunity – The elderly Antiviral medication available for shingles on prescription include: – Aciclovir (this is the only one available in New Zealand) – Valaciclovir – Famciclovir

Molluscum contagiosum Molluscum contagiosum is a common viral skin infection. It most often affects infants and young children but adults may also be infected. Molluscum contagiosum presents as clusters of small round bumps (papules) especially in the warm moist places such as the armpit, groin or behind the knees. They range in size from 1 to 6 mm and may be white, pink or brown. They often have a waxy, pinkish look with a small central pit (umbilicated). As they resolve, they may become inflamed, crusted or scabby. There may be few or hundreds of spots on one individual. Molluscum contagiosum is a harmless virus but it may persist for months or occasionally for a couple of years. It frequently induces a type of dermatitis in the affected areas, which are dry, pink and itchy. Molluscum contagiosum may rarely leave tiny pit-like scars.

How do you catch molluscum contagiosum? Molluscum contagiosum can be spread from person to person (especially children) by direct skin contact. This appears to be more likely in wet conditions, such as when children bathe or swim together. Sexual transmission is possible in adults. Lesions tend to be more numerous and last longer in children who also have atopic eczema. It can be very extensive and troublesome in patients with human immunodeficiency virus infection. Molluscum contagiosum may arise in areas that have been injured, often because they've been scratched. The papules form a row; this is known as

Treatment There is no single perfect treatment of molluscum contagiosum since we are currently unable to kill the virus. The soft white core can be squeezed out of individual lesions. In many cases no specific treatment is necessary. Medical treatments include: • Minor surgery, curettage (topical anaesthetic cream may be applied first) or laser ablation • Cryotherapy • Cantharidine • Imiquimod cream • Wart paints containing salicylic acid or podophyllin The dermatitis may be treated with hydrocortisone cream, but is unlikely to fully resolve until the infection has cleared up.

Viral warts Warts are tumours or growths of the skin caused by infection with Human Papillomavirus (HPV). More than 70 HPV subtypes are known. Warts are particularly common in childhood and are spread by direct contact or autoinocculation. This means if a wart is scratched, the viral particles may be spread to another area of skin. It may take as long as twelve months for the wart to first appear.

What do they look like? • • • • • • • •

Warts have a hard ‘warty’ or ‘verrucous’ surface. You can often see a tiny black dot in the middle of each scaly spot, due to a thrombosed capillary blood vessel. There are various types of viral wart. Common warts arise most often on the backs of fingers or toes, and on the knees. Plantar warts (verrucas) include one or more tender inwardly growing ‘myrmecia’ on the sole of the foot. Mosaic warts on the sole of the foot are in clusters over an area sometimes several centimetres in diameter. Plane, or flat, warts can be very numerous and may be inoculated by shaving. Periungual warts prefer to grow at the sides or under the nails and can distort nail growth. Filiform warts are on a long stalk. Oral warts can affect the lips and even inside the cheeks. They include squamous cell papillomas. Genital warts are often transmitted sexually and predispose to cervical, penile and vulval cancer.

Treatment Occlusion • Just keeping the wart covered 24 hours of the day may result in clearance. Duct tape is convenient and inexpensive. Chemical treatment. • Chemical treatment includes wart paints containing salicylic acid or similar compounds, which work by removing the dead surface skin cells. Podophyllin is a cytotoxic agent, and must not be used in pregnancy or in women considering pregnancy. • The paint is normally applied once daily. Perseverance is essential - although 70% of warts will go with wart paints, it may take twelve weeks to work! Even if the wart doesn't go completely, the wart paint usually makes it smaller and less uncomfortable.

Cryotherapy • The wart is frozen with liquid nitrogen repeatedly, at one to three week intervals. This is uncomfortable for a few minutes and may result in blistering for several days. Success is in the order of 70% after 3-4 months of regular freezing. Dermatologists debate whether a light freeze to stimulate immunity is sufficient, or whether a harder freeze is necessary to destroy all the infected skin. A hard freeze might cause a permanent white mark or scar. Electrosurgery • Electrosurgery (curettage & cautery) is used for particularly large and annoying warts. Under local anaesthetic, the growth is pared away and the base burned by diathermy or cautery. The wound heals in about two weeks; even then 20% of warts can be expected to recur within a few months. Other treatments • There are numerous treatments for warts and none offer a guarantee of cure. They include bleomycin injections, laser vaporisation, pulse dye laser, oral acitretin and immune modulators such as imiquimod cream.

Orf Orf is a virus infection of the skin contracted from sheep and goats. Orf is caused by a virus called the parapox virus, which infects mainly young lambs and goats who contract the infection from one another or possibly from persistence of the virus in the pastures. Human lesions are caused by direct inoculation of infected material.

Treatment No specific treatment is necessary in most cases, as orf usually clears up by itself in about 6 weeks. The lesion may be covered to prevent contaminating the environment or other people, although person-to person spread is very uncommon. Any secondary bacterial infection should be treated. Large lesions can be removed by shave excision. Imiquimod cream has been reported to be effective in a few cases of orf.

Complications Patients whose immunity is reduced for some reason may develop larger or unusual orf lesions. Rarely widespread small blisters may occur, suggesting blood stream spread of the orf virus, but resolve after a few weeks. A secondary allergy rash to the presence of the orf virus, erythema multiforme, occasionally develops, typically 10-14 days after the onset of orf, to give small blistery red ring-like lesions on the arms and legs. Less distinctive red rashes, 'toxic erythemas' also occur and rarely the blistering disorder pemphigoid.

Milker's nodules Milker's nodule is an infection of the skin caused by a virus that infects the teats of cows. It is sometimes called cowpock although it is important to note this is a different condition from cowpox (in recent reports from Europe, cowpox has been acquired from cats and small rodents rather than cows).

Causes Milker's nodule is caused by a parapox virus. It produces mild infections of the teats of cows, i.e. ring sores, as well as ulcers in the mouths of calves. It is similar to bovine papular stomatitis virus, which affects the same sites in cattle. The two viruses are variants. Both can produce lesions on the hands of dairy farmers or vets who examine the mouths of animals. Human infection is from contact with infected lesions on the animals. Human-to-human spread appears not to have been recorded. Orf is another parapox virus that affects sheep and goats.

Sign and Symptoms After an incubation period of 5-14 days small, red, raised, flat-topped spots develop. Within a week they appear as red-blue, firm, slightly tender blisters or nodules (lumps), usually between 2 and 5 in number although they may be solitary or more numerous. The nodules are usually on the hands, particularly the fingers, but occasionally the face. The top of the nodules often develops a greyish skin and a small crust. There maybe secondary bacterial infection. Many patients develop red streaks up the lymph channels on the arms and some enlargement of the lymph glands.

Treatment The nodules can just be left to resolve spontaneously over 4-6 weeks. They should be covered to prevent contamination of the environment and also potential spread to other people. Gloves should be worn if milking. Any secondary bacterial infection should be treated.

Erythema multiforme Erythema Multiforme (EM) is a hypersensitivity reaction usually triggered by infections, most commonly herpes simplex virus (HSV). It presents with a skin eruption characterised by a typical target (iris) lesion. There may be mucous membrane involvement. It is acute and self-limiting, usually resolving without complications. Erythema Multiforme major and minor forms and is now regarded as probably distinct from Stevens Johnson Syndrome (SJS) and T oxic Epidermal Necrolysis (TEN)

Symptoms There are usually no prodromal symptoms (EM minor). However, sometimes with EM major there may be mild symptoms such as fever or chills, weakness or painful joints.

Treatment For the majority of cases, no treatment is required as the rash settles by itself over several weeks without complications. Treatment directed to any possible cause may be required such as oral aciclovir (not topical) for HSV or antibiotics (e.g. erythromycin) for Mycoplasma pneumoniae. If a drug cause is suspected then the possible offending drug should be ceased.

• • • •

Supportive/symptomatic treatment may be necessary. Itch – oral antihistamines and/or topical corticosteroids may help. Oral pain – mouthwashes containing local anaesthetic and antiseptic reduce pain and secondary infection. Eye involvement should be assessed and treated by an ophthalmologist. EM major may require hospital admission for supportive care, particularly if severe oral involvement restricts drinking.

The role of oral corticosteroids remains controversial as no controlled studies have shown any benefit. However for severe disease 0.51mg/kg/d prednis(ol)one is often used early in the disease process. Recurrent EM is usually treated initially with continuous oral aciclovir for 6 months at a dose of 10mg/kg/d in divided doses (e.g., 400mg twice daily), even if HSV has not been an obvious trigger for the patient's EM. This has been shown to be effective in placebo-controlled double blind studies. However EM may recur when the aciclovir is ceased. Other antiviral drugs such as valciclovir (500-1000mg/d) and famciclovir (250mg twice daily) should be tried if aciclovir has not helped; these drugs are not readily available in New Zealand.

• • • •

Other treatments (used continuously) that have been reported to help suppress recurrent EM include: Dapsone 100-150mg/d Antimalarial drugs eg hydroxychloroquine Azathioprine 100-150 mg/d Others thalidomide, ciclosporin, mycophenolate mofetil, photochemotherapy (PUVA).

Erythema nodosum Erythema nodosum is a skin condition where red lumps form on the shins, and less commonly the thighs and forearms. It is a type of panniculitis.

Causes • Throat infections; these may be due to streptococccus, or viral in origin. • Sarcoidosis; EN is often associated with enlargement of the lymph nodes (bihilar lymphadenopathy) in the lungs in sarcoidosis. This is known as Lofgren's syndrome. It may result in a dry cough or some shortness of breath. • Tuberculosis (TB); EN occurs with the primary infection with TB. TB in New Zealand is currently uncommon. • Pregnancy or the oral contraceptive pill; EN may occur after the first 2 or 3 cycles on the pill. EN may occur in pregnancy, clear after delivery, then recur in subsequent pregnancies. • Other drugs; other drugs which can cause EN include: sulphonamides, saliclyates, bromides, iodides and gold salts. • Other causes; there are many other causes of EN but these are uncommon in New Zealand.

Treatment • Bed rest is advised for severe EN. • Firm supportive bandages or stockings should be worn. • Aspirin or other anti-inflammatory medication. • A course of potassium iodide is often effective in clearing it. Mild cases subside in 3 weeks, more severe ones in about 6 weeks. Cropping of new lesions may occur within this time, especially if the patient is not resting

Gloriani, Kevin Patrick Gonzales, Diane Joyce Gozales, Karla Jane Levita, Ailyn Martinez, Jussel Merlan, Mariel

Mrs. Michelle T. Bono