Scabies (Sarcoptes Scabiei)



  • Is in the arthropod class Arachnida, subclass Acari, family Sarcoptidae
  • Animal scabies or mange (Sarcoptes scabiei) can burrow but cannot reproduce on human hosts
  • Gravid females form burrows where they deposit up to 2–3 eggs per day into the stratum corneum along with feces, skin moults, and saliva
  • Secondary infections can occur and are usually due to Staphylococcus aureus or β-hemolytic streptococci and may predispose to renal and cardiac sequelae
  • Scabies is a major global health problem in crowded, resource-poor communities and refugee populations

Pediatric Considerations
  • Scabies may present differently in children:
    • More inflammatory (vesicular or bullous)
    • Involvement of face, scalp, palms, or soles
  • Highest prevalence is in children <2 yr old


  • Epidemiology:
    • Prevalence reports are wide ranging
    • WHO reports up to 130 million infected at any time
    • Burden of disease is highest in countries with hot, tropical climates, especially where overcrowding and poverty coexist
  • Transmitted by (15–20 min) direct skin-to-skin contact or, less commonly, by infested bedding or clothing:
    • It is a disease of overcrowding and poverty, rather than a reflection of poor hygiene
    • Family members, sexual contacts, and institutional settings are at high risk for transmission
  • Symptoms result from delayed (2–4 wk in first exposures) type IV hypersensitivity reaction to mite, eggs, saliva, and feces:
    • Inflammatory reaction leads to intense nocturnal pruritus, which is a hallmark
    • Crusted scabies (Norwegian) is characterized by massive infestation with up to millions mites and is highly contagious and is more common in immunocompromised patients
  • Mites subsist on a diet of dissolved human tissue (do not feed on blood) and can live up to 3 d off a host's body
  • On average, the number of mites on a host at any time is ∼5–15 unless crusted which suggests massive infestation

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