ID Flashcards
Name the 3 types of mycetoma and examples of organisms that cause each.
Actinomycotic mycetoma: filamentous aerobic/anaerobic orgs (e.g. Nocardia brasiliensis, Actinomadura madurae)
Eumycotic mycetoma: true fungi (e.g. Acremonium, Aspergillus, Fusarium, Pseudoallescheria boydii, Exophiala, Curvularia, Madurella, Leptosphaeria, Pyrenochaeta)
Botryomycosis: true bacteria (e.g. S.aureus, Pseudomonas)
The human body louse transmits:
Trench fever
Relapsing fever
Epidemic typhus
What organism causes white piedra?
Trichosporon cutaneum (formerly T.beigelii), T.ovoides, T.inkin, T.asahii (Black Piedra = Piedraia hortae)
What HLA type is associated with recurrent HSV-related erythema multiforme?
HLA B15
Differential diagnosis of lesions that look like molluscum.
Coccidiodomycosis, cryptococcus, histoplasmosis, penicilliosis
What causes milker’s nodule?
Paravaccinia virus (a poxvirus of genus parapoxvirus)
Name the Dermatophytes.
Trichophyton, Microsporum, Epidermophyton
Most common = T.rubrum
What are the causes of tinea capitis with FLUORESCENT ECTOTHRIX?
“Cats And Dogs Fight and Growl Sometimes”
M. canis M. auduoinii M. distortum M.ferrugineum M.gypseum T.schoenleinii
(All Microsporum except last one)
What are the causes of ENDOTHRIX
“Ringo Gave Yoko Two Squeaky Violins”
T.rubrum (can cause endo/ecto) T. gourvilli T. yaounde T.tonsurans T.soudanense T. violaceum
(note that all are Trichophyton; none fluoresce)
What causes a positive Wood’s lamp exam?
PTERIDINE in dermatophytes (Cats and Dogs…)
COPROPORPHYRIN III (Corynebacterium)
PYOCYANIN (Pseudomonas)
Ddx of Sporotrichoid Spread?
Most common = atypical mycobacteria (M. marinum > M.chelonae, M.kansasii), Sporotrichosis (Sporothrix schenckii), Nocardiosis, Pyogenic bacteria (Staph aureus, Strep pyogenes), Pseudoallescheria boydii; Leishmaniasis, Tularemia, TB, other dimorphic fungi, opportunistic fungi, Glanders, Cat-scratch disease, Anthrax, Cowpox, Acanthamoeba species; don’t forget melanoma!
What causes favus-type tinea capitis? What is the charactieristic hair finding on KOH exam?
T.schoenleinii, T.violaceum, M.gypseum (She’s a Violent Gypsy)
On KOH you see arthroconidia and airspaces within hair shaft
What causes seabathers eruption? What is presentation? How can it be prevented?
Cause: jellyfish larvae (Linuche unguiculata); itchy rash under BATHING suit after swimming in the SEA; prevent by washing off after swimming.
Compare to Swimmer’s itch – fresh water, exposed skin, caused by avian schistosomes)
Heck’s disease (focal epithelial hyperplasia) is caused by which HPV types?
HPV 13 and 32
Which HPV causes common warts?
HPV 1, 2, 4
Which HPV causes Butcher’s warts?
HPV 2 and 7
Which HPV most commonly causes epidermodysplasia verruciformis? Mutations?
HPV 5; others include 2, 3, 8-10, 12, 14, 15, 17 (SCC In EV associated with 5 and 8)
Mutations: EVER1 (TMC6) and EVER2 (TMC8) - warts forever and ever
Which HPV most commonly causes epidermodysplasia verruciformis? Mutations? Treatment?
HPV 5; others include 2, 3, 8-10, 12, 14, 15, 17 (SCC In EV associated with 5 and 8)
Mutations: EVER1 (TMC6) and EVER2 (TMC8) - warts forever and ever
Tx: Soriatane
What are the live vaccines?
“MMR Vaccines Suck For Your Old Patients Taking Biologics”
MMR VZV Smallpox Flumist (nasal flu) Yellow fever Oral (oral Polio and oral Typhoid; injectable versions are killed) BCG
Bowenoid papulosis, cervical cancer and periungual SCC are associated with which HPV types?
HPV 16 and 18; others 31, 33, 51
What bugs cause chromomycoses? What is charactistic histopath finding?
“Pedro’s Compact Car is Very Wet”
Fonseaca pedrosei (#1) Fonseaca compacta Cladosporium carrionii Phialophora verrucosa Rhinocladiella aquaspersa
Finding = Medlar bodies, “copper pennies,” typically in groups.
What is the treatment for M.marinum infection?
Minocycline (or doxy, bactrim, clarithromycin) for 1-2 months after lesions resolve
What is the cause of bullous tinea pedis?
T.mentagrophytes
What is Ramsay Hunt syndrome? Treatment?
VZV infection of geniculate ganglion; presents with ipsilateral facial paralysis, tinnitus/auditory symptoms. Vesicles on external ear and/or tympanic membrane.
Tx = acyclovir and steroids.
