Table - Microbiology, Parasitology, Virology

ID for boards –  boards –  pg  pg 1

Staphylococcus Non-bullous Impetigo 70% of impetigo

Bullous Impetigo 30% of impetigo

Staph Scalded Skin Synd “SSSS” / “Ritter's disease” “Pemphigus neonatorum”

Toxic Shock Synd “TSS”

Scarletiniform Eruption “Staph Scarlet Fever”

G+ cocci in chains Classic impetigo Honey-crust near nose “impetigo” = superficial pyoderma

S. aureus phage II type 71 toxin

Nikolsky‟s sign + in lesional & uninvolved skin; Path: split @ granular layer . Mortality: Kids Mortality: Kids 3%, Adults >50%.

S. aureus phage II

15-35yo w/ sudden onset, very sick, erythrodermic rash & mucositis Blood cx: + adults)

Botryomycosis

S. aureus >

Grains on light microscopy „blue clouds of bacteria‟

Fingertip infection (thumb,index) from trauma (splinter, glucose stick) From trauma Adult paronychia more assoc w/ HSV necrosis of subcutis & fascia unresponsive to Abx. Extremities >> Fournier‟s (perineum) splinter hemorrhages, Osler's nodes, Janeway lesions, and petechial lesions

(3A,3C,55,71) Exfoliative toxins

ET-A, ET-B

Staph aureus: TSST-1 Enterotoxins B + C Surgical packing, mesh, abscess, tampon

Staph aureus: TSST-1 Kids:  S.aureus > H.flu Adults: GAS >> S.aureus S.aureus occlusion/maceration/steroids at face, chest, back, buttocks > Gram neg (back acne) > Pseudomonas (ho tub)

S.aureus > P.aeruginosa, E.coli, Proteus

S.aureus S.aureus, Strep p yogenes 90% polymicrobial (type 1) 1)

10% GAS (type 2): M-protein

Clinical: 4mm red papule → honey-crusted honey-crusted vesicle;  vesicle; at face/nose or arm/hand. 5% of Strep pyogenes Strep pyogenes → Acute post-strep post-strep GN. Test: anti-DNase B antibodies tests antibodies tests for Staph impetigo only). Clinical: flaccid large bullae → “varnish-like erosion” w/ weakness, fever, diarrhea. diarrhea. Tx: bactroban, keflex or augmentin, (β-lactam (β-lactam resistant), clarith/azithromycin. Patho: ET-A Patho: ET-A (chr), ET-B (plasmid) bind desmoglien 1 at granular layer → sterile bullae. bullae . Distant S.aureus infection; often nasal carraige carraige Clinical: lungs nodules, verrucous plaques → sinuses sinuses / fistulae Risk factors: HIV, diabetes, trauma, alcoholism Histo: 1-3mm  1-3mm granular „clubs‟ = bacteria, cells, and debris

closed-space infections of the fingertip pulp Clinical: Swollen, red, painful digit following minor nail trauma Adult paronychia assoc w/ HSV Clinical: Refractory cellulitis (red → blue/gray blue/gray), ), hardens, F/C → shock  Assoc w/ DM, ETOH, CAD, PVD, s/p blunt trauma or recent surgery Osler‟s nodes - tender, red nodules w/ white centers on finger pads & thenar, hypothenar Janeway lesions  - painless, small hemorrhagic macules or papules on the palms and soles

Large, G+ rods; α-toxin (destroys cell membranes, hemolysis), hemolysis), θ-toxin (hemolysis, muscle necrosis, & cardiac toxicity); Tx: PCN G (+ Clinda + Aminoglycoside as 50% polymicrobial cellulitis with crepitus spares deep fascia & muscle >3d incubation deep anaerobic cellulitis to muscle & fascia w/ toxemia fast incubation > post-op post -op bowel or GB surgery Clinical: foul painful necrotic nodules; toxic, bronze skin, bullae w/ brown fluid

ID for boards –  pg 2

Streptococcus Strep Toxic Shock Synd “STSS” “Toxic Strep Synd”

Ecthyma

Scarlet Fever “Scarletina”

Erysipelas “St Anthony's fire”

Strep perianal disease “Perianal Cellulitis”

Purpura Fulminans Blistering Distal Dactylitis

G+ cocci in clusters 20-50 yo w/ any GAS infection, PAINFUL skin → early shock & organ failure Blood cx: + >50%; ↑mortality Super-Antigen Syndrome: M-protein Ulcerated non-bullous impetigo extends into dermis no systemic symptoms

Prodrome: fever & sore throat → “sunburn w/ goosebumps”, Staw/Beefy Tongue, Pastia‟s lines. → peeling skin 2-10yo kids.  No rash in children w/ Antibodies: 80% by 10yo

GAS (S. Pyogenes) Lacerations, Bites, Bruises, Varicella Super-Ag: Strep M proteins

GAS (S. Pyogenes)  staph superinfection

→

GAS infection after tonsillitis/pharyngitis.

Erythrogenic toxins A,B,C

Dermal GAS infection w/out lymphatic or subcutis involved

GAS (S. Pyogenes)

Perianal erysipelas, kids 2), HA, lymphocytoma, myalgias, rash Rash: Erythematous or petechial macules on trunk & extremities Tx: Doxycycline

(Western US) Tx: Doxy 100mg BID x 7d

Borrelia duttonii / hermsii

-6A, -7 CD4+ lymphotropic viruses; Transmitted through saliva Castleman‟s syndrome >60 yo Mediterranean or Ashkenazi Jew; HIV+ Kaposi‟s sarcoma 1. classic KS –  spongy feel (early) → purplish-red plaques on LEs of elderly Mediterranean men (slow progression) 2. HIV/AIDS KS – small macules, plaques become exophytic & ulcerative → i nvolves oral & perioral, genital, GI tract 3. Immunosuppressed KS –  similar to AIDS-KS with rapid dissemination 4. African endemic KS -- nodular (benign), lymphadenopathic, florid, infiltrative (aggressive).

Hand-Foot & Mouth Dz

Cocksackie A16 > Enterovirus 71

Herpangina

Coxsackievirus Group A

Measles / Rubeola

Paramyxovirus Paravaccinia virus (Parapoxvirus) 

Milker‟s Nodule Orf

Orf virus

Contagious Pustular Dermatitis Contagious Ecthyma

(Parapoxvirus)

Fifth Disease Erythema Infectiosum

6 stages (each last 6 days): 1. Papular (red papule), 2. Target (erythematous w/ white ring); 3. Acute (weeping) 4. Regenerative (crusts w/ black dots); 5. Papillomatous (small papillomas); 6. Regressive (crusts, flat)

Kids: Slapped-cheek appearance Adults: acute arthropathy w/ fever & adenopathy; ± lacy reticular mac ular eruption Pregnancy: Hydrops fetalis, spont Ab if 1 st ½ of preg; Sicklers: Aplastic crisis; Immunocompromised pts: severe chronic anemia

Parvovirus B19 (ss-DNA) Molluscum contagiosum virus

Molluscum contagiosum

Umbilicated papules; kids>adults

(Poxvirus)

16d incubation. Rash: Erythematous maculopapular FACE to trunk in 24h (disappears as it spreads); Tender lymphadenopathy (occipital, posterior auricular); + Joint involvement Forchheimer‟s spots (soft palate petechial macules) TORCH syndrome w/ Blueberry Muffin Baby (low birth wt, microcephaly, cong heart dz) TORCH syndrome: HSM, deafness, microcephaly, chorioretinitis, thrombocytopenia Blueberry Muffin Baby: dermal extramedullary erythropoiesis; Gen. 1-7mm purpuric papules on H/N/trunk 12d → Prodrome 3d F/HA/N/V, back pain; ± pathognomonic swimming trunk distrib. Petechiae Generalized centrifugal eruption: eruption of umbilicated papules, deep vesicles, pustules, crusts Dx: Guarnieri‟s bodies (cytoplasmic eosinophilic bodies) on LM; Fluorescent Ab staining lesion fluid

Rubella (nasopharynx infection) (Togavirus)

Rubella / German measles Rubella (congenital infection) (Togavirus)

Variola (Poxvirus) Smallpox

Smallpox complications:

ID for boards –  pg 9 Erythematous papules w/ grayish vesicle & surrounding red areola Transmission: oral-oral & oral-fecal Fever, Headache, Cervical Lymphadenopathy Gray-white papulovesicles on tonsillar fauces, palate → ulcerate 3d prodrome of: High Fever + 3 C‟s (cough, coryza, conjunctivitis); → Koplik‟s spots th Rash: Erythematous macules & papules begins on forehead, then generalizes (fades on 5  day) Complications: otitis, PNA, encephalitis, myocarditis, subacute sclerocing panencephalitis (sz, coma) Transmit: infected cows → humans Single 1cm erythematous targetoid nodule on finger/forearm (may be multiple); Self-limited Endemic: sheep, goats, musk oxen (nodules on nose/mouth) → transmitted to shepherds, farmers, vets Clinical: Papule/nodule on dorsal index finger;

EM-like eruptions Bacterial Superinfection Accidental inoculation Congenital vaccinia Generalized vaccinia Progressive vaccinia

S.aureus, GAS Eczema vaccinatum p innoculation onto dermatitic skin Following vaccination of a pregnant woman Children w/ isolated IgM deficiency are especially prone (ie. Wiscott-Aldrich Synd) Impaired immunological response to vaccinia (in normal or immunodeficient hosts)

Human Papillomavirus (HPV) Type of wart Palmo-plantar Common, myrmecial Flat Butcher‟s Heck‟s dz (Oral focal epithelial hyperplasia) Epidermodysplasia verruciformis (EDV) Anogenital; Buschke-Lowenstein tumor High risk anogenital/cervical CA; Bowenoid Papulosis

HPV type 1 2,4 3,10 7 (2) 13,32 3, 5,8 > 9,12,14,15,17,19-26 6,11 16 >18,31,33-35

DNA Viruses: H-H-A-P-P-P-y

RNA Viruses: P-P-R-R-T

herpes, hepadna, adeno,  papova, ss-parvo, pox Paramyxovirus (measles, mumps); Picornavirus (Enterovirus: coxsackie) Retrovirus (HIV, HTLV); Rhabdovirus (rabies); Togavirus (rubella);

ID for boards –  pg 10

Lice, Mites, Spiders, Bugs Black widow

L actodectus mactans

Brown recluse

L oxosceles

Wolf spider Jumping spider Sac spider Hobo spider Green Lynx spider Tarantulas Scorpions Catepillars Bee, wasp, hornet, ant Fire ants Black flies Horseflies, Deerflies, Mangoflies Sand flies Mosquitoes: Malaria Mosquitoes: Yellow Fever & Dengue Bedbugs Fleas: Typhus & Plague Centipedes Millipedes

L ycosidae Phidippus Chiracanthium Tegenaria agrestis Peucetia viri dans Centuroides sculpturatus/gertschi Lepidoptera Hymenoptera Solenopsis (invicta) Tabandae Anopheles Aedes Cimicidae Pulex irr itans 

Chilopoda Diploda

White hourglass on abdomen; painful bites, but no necrosis. Antivenin helpful