Scabies

Background

• Infestation with the Sarcoptes scabiei mite
• 4-6wk incubation period after initial exposure
  • Those previously infected, sx begin in 1-3 days (sensitization)
• Not a reflection of poor hygiene

Diagnosis

Must elicit history of symptomatic close contacts (human or animal)

• Older children / adults
  • Generalized eruption w/ linear burrows, papules, pustules
  • Hand, feet, groin predominance
• Infants
  • Hyperpigmented nodules, vesiculopustules, papules may be found in axilla and diaper areas
  • May be generalized

DDx

• Impetigo
• Atopic dermatitis
• Insect bites
• Drug reaction
• Dermititis Herpetiformis

Treatment

• Permethrin 5% cream for all family members
  • Apply from neck down
  • Infants may require applicatio nto scalp/face (avoid mucus membranes)
  • Leave on for 8-12hr before washing off
  • Has 95-98% success rate, may reapply in 1-2wks if incomplete effect
• Ivermectin 200mcg/kg may be necessary for severe infection
  • Also viable option in adolescent or adult with insecure social situation
  • Success rate 70%, increases if give repeat dose 2wks after
  • Contraindicated in lactating women and children < 15kg
• Wash linens/clothes in hot water or bag bulky items and keep sealed for 2wks
• Pruritus may continue for weeks despite successful elimination of infestation

Source

Tintinalli