Scabies
Background
- Saccoptes scabiae var. hominis
- Female burrows through skin (finegr webs, elbows, wrists)
- 2-3 eggs per day in burrow (for up to 2 months!)
- Larvae emerge 3 days later
- Live cycle complete in 10-14 days. Mites live circa 30 days
- Incubation period (1st) 2-4 weeks - allergic reaction develops to mite faeces
Clinical
- Itch , rash, papules
- Scrathcing and eventual lichenification
- Hands,(finger webs), wrists, elbows, male genitalia, buttocks, axillae
- ( In contrast allergic rxn unually midrif, inside thighs axilae, legs)
Diagnosis
- Hx often very persuasive!
- ID burrow with mite at one end (good light, magnifying glass)
- Crusted ("Norwegian") scabies found in elderly, alcoholics, Down's syndrome, AIDS, immunosuppressed
Treatment
- Oral antihistamines (itch) if required
- Permethrin (or malathion)
- Household contacts trated AT SAME TIME
- Two treatments, one week apart
- Asymptomatic contacts (> 10 minutes contact) need one treatment
Notes
- Anybody else at home got itch?
- 80% of males have genital involvement
- No head / neck involvement as too cold
- Don’t look for burrows treat on Hx alone. GP to refer dermatology if fails
