262. Bugs/Parasites Flashcards
Tinea Corporis
what it is, skin, KOH
Ringworm
Annular/Circnet erythematous plaques with central clearing
KOH: septate hyphae (Beads on string)
Tinea Capitus (KOH, variations)
Spores on hair shaft
Ectothrix: inside hair shaft
Endothrix: outside hair shaft
Tinea Versicolor
skin, KOH
Slightly scaly thin oval plaques
KOH: spaghetti + meatballs of round spheres/long hyphae
Herpesvirus Infection: KOH
multinucleated giant cell
Scabies
KOH Dx, Skin, Location, Transmission, Life Cycle, Advanced type, Tx
KOH: 6 legged mite, egg, scybala (mite feces)
Skin: scaly crusty red papules, linear burrows
in warm areas: Fingerwebs, skin folds, belly button, axilla, groin
Transmission: SKIN-TO-SKIN - contagious
Life Cycle: lay 3 eggs/day, egg to adult in 10-14 days
“Norwegian Scabies” in immunocompromised - crusted presentation, thick scaly plaques all over (hundreds-millions mites instead of 5-15)
Tx: Topicals (Permethrin) NEED TO TX ALL CLOSE CONTACTS (can be transmitted through infested bedding/clothing
Epidemic Typhus
what it is, transmission, locations
Human body louse
lives in seems of unwashed clothes - transmitted by people, bites people
Scalp/Head Lice remove with special combs and rinses
Crab Louse
what it is, transmission
Pubic Louse
spreads through sexual contact
Erythema (Chronica) Migrans
what it is, skin
Lyme Disease from Borrelia burgdorferi (spirochete) from Ixodes tick
Most common vector-borne infection in US
Initial erythematous papule/macule enlarges within days to form expanding annular lesion with red border with central redness (target)
Bedbugs
skin, where they reside, rxns, eliminations
Multiple small bites on exposed sites, 2-3x in a row
Reside in crevices of bedding, furniture, floor and wall - come out in warmth/CO2
Can cause intense pruritic papules, urticaria, bullae in sensitized patients at bite sites
Kill bed bugs via exterminator, trap them with bean leaves, sniff em out with dogs
Tunga Penetrans (Tungiasis) (what it is, how you get it, skin)
Chigoe flea burrows into skin, lays eggs
When pt doesn’t wear closed toed shoes in tropics
Crusted papule, visible eggs on toes
Myiasis
what it is, skin, prognosis
Parasitic infection from fly larvae (maggots), grow in host, feed on tissue
Crusted opening with surrounding erythema, swelling
Usually resolves itself
Dermatobia Hominis
what it is, prevention
Bot Fly larvae gets under skin via mosquito bite
Prevention: wear long clothes/hats in tropics
Usually don’t spread past skin
