Sarcoptes scabiae - Thank You to NEJM
Scabies burrows often found in finger web spaces


  • Sacoptes scabiae var. hominis
  • Female burrows through skin (finger 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


  • Itch , rash, papules
  • Scratching and eventual lichenification
  • Hands,(finger webs), wrists, elbows, male genitalia, buttocks, axillae.
    • ( In contrast allergic Rxn usually midriff, inside thighs axillae, legs)


  • 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


  • Oral antihistamines (itch) if required
  • Permethrin (or malathion)
  • Household contacts treated AT SAME TIME
  • Two treatments, one week apart
  • Asymptomatic contacts (> 10 minutes contact) need one treatment


  • 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

Content by Dr Íomhar O' Sullivan 14/03/2009. Last review Dr ÍOS 10/06/21.