What is the recommended treatment for scabies and how to treat the environment to prevent re-infestation?

Scabies Treatment and Environmental Management

For scabies treatment, permethrin 5% cream applied to all areas of the body from the neck down and washed off after 8-14 hours is the first-line treatment, with oral ivermectin 200 μg/kg as an effective alternative. All bedding and clothing must be decontaminated by machine washing/drying using heat cycle or removed from body contact for at least 72 hours to prevent reinfestation. 1

First-Line Treatment Options

Topical Treatments

• Permethrin 5% cream
  • Apply to all areas of the body from the neck down
  • Leave on for 8-14 hours, then wash off
  • Safe, effective, and less expensive than ivermectin 2, 1
  • FDA-approved for scabies treatment 3

Oral Treatment

• Ivermectin 200 μg/kg orally
  • Take with food to increase bioavailability
  • Repeat dose after 2 weeks (limited ovicidal activity)
  • Particularly useful for widespread or severe infestations 2, 1

Alternative Treatments

• Lindane 1% lotion or cream

  • Apply thinly to all areas from neck down
  • Wash off after 8 hours
  • CAUTION: Should not be used after bathing, in patients with extensive dermatitis, pregnant/lactating women, or children under 2 years 2
  • Only use if other treatments fail due to potential toxicity

• Crotamiton 10%

  • Apply to entire body from neck down
  • Apply nightly for 2 consecutive nights
  • Wash off 24 hours after second application 2

• Sulfur 6-33% preparations

  • Some recent evidence suggests 10% sulfur ointment may be effective, particularly where permethrin resistance is emerging 4

Environmental Decontamination

Essential Steps

1. Bedding and clothing decontamination

   • Machine wash and dry using hot cycle
   • Dry clean affected items
   • OR remove from body contact for at least 72 hours 2, 1

2. Household management

   • Fumigation of living areas is NOT necessary 2, 1
   • Focus on items that have been in direct contact with the patient

Contact Management

• All household members and close contacts should be treated simultaneously, even if asymptomatic 1
• Sexual partners within the previous month should be treated 2, 1

Special Populations

Children

• Infants and young children should be treated with permethrin 2
• Children under 10 years should not be treated with lindane 2
• Pay special attention to the scalp, temple, and forehead in infants 1

Pregnant/Lactating Women

• Permethrin 5% cream is the treatment of choice 2, 1
• Avoid lindane due to potential neurotoxicity 2, 3

Immunocompromised Patients

• At higher risk for crusted (Norwegian) scabies
• May require combination therapy with topical agents and oral ivermectin 1
• Consider specialist consultation

Follow-Up and Treatment Evaluation

• Evaluate treatment effectiveness after 2-4 weeks 1
• Persistent pruritus may continue for up to 2 weeks after successful treatment 1, 3
• Consider retreatment if:
  • Symptoms persist beyond 2 weeks
  • Live mites are observed
  • New lesions appear 1

Common Pitfalls to Avoid

1. Inadequate treatment application

   • Ensure complete coverage from neck down (include all skin folds, between fingers/toes)
   • Follow recommended duration before washing off

2. Failure to treat all contacts

   • Reinfestation commonly occurs when not all household/close contacts are treated simultaneously

3. Mistaking post-scabetic itch for treatment failure

   • Pruritus may persist for several weeks after successful treatment 2, 1, 3

4. Inadequate environmental decontamination

   • Failure to properly clean bedding and clothing can lead to reinfestation

5. Overuse of lindane

   • Can cause toxicity including seizures and aplastic anemia 2