What is the recommended treatment for scabies?

Recommended Treatment for Scabies

Permethrin 5% cream is the first-line treatment for scabies, applied from neck to soles of feet (including head/scalp in infants and elderly) for 8-14 hours, with one application generally being curative. 1, 2

First-Line Treatment Protocol

1. Permethrin 5% cream application:

   • Apply thoroughly from head to soles of feet (adults typically need about 30g)
   • Leave on for 8-14 hours then wash off with shower or bath
   • One application is usually sufficient with cure rates of 89-95% at 4 weeks 1
   • For infants, elderly, and immunocompromised patients, include treatment of scalp, temple, and forehead 2, 3

2. Important considerations:

   • Persistent itching after treatment is common and not necessarily a sign of treatment failure 2
   • Only retreat if living mites are found after 14 days 2
   • Simultaneously treat all household members and close contacts, even if asymptomatic 1

Alternative Treatments

When permethrin fails or is contraindicated:

1. Oral ivermectin:

   • Dosage: 200 μg/kg body weight
   • Should be repeated after 14 days due to limited ovicidal activity 1
   • Take with food to increase bioavailability
   • Single-dose cure rates are lower (62.4%) compared to permethrin (96.9%), but increase to 92.8% with a second dose 4

2. Other alternatives:

   • Benzyl benzoate 25% lotion 5
   • Malathion 0.5% aqueous lotion 5
   • Ivermectin 1% lotion 5
   • Sulfur 6-33% preparations 5

Special Populations

1. Crusted (Norwegian) scabies:

   • Requires combination therapy with topical scabicide and oral ivermectin 5
   • May need multiple treatments due to high parasite burden

2. Pregnancy and lactation:

   • Permethrin 5% is preferred due to established safety data 1

3. Children:

   • Permethrin 5% is first choice for all ages 1
   • Avoid ivermectin in children under 15kg 1
   • Avoid lindane in children under 10 years due to neurotoxicity risk 1

4. Impetiginized scabies:

   • Consider combination of permethrin 5% with fusidic acid 2% cream for secondary bacterial infections 6
   • Staphylococcus aureus is the most common secondary bacterial pathogen 6

Environmental Control

• Machine wash bedding and clothing in hot water cycle or keep items out of body contact for at least 72 hours 1
• No need for extensive environmental cleaning as mites cannot survive long off the human body

Common Pitfalls and Caveats

1. Treatment failures often result from:

   • Inadequate application (not covering all affected areas)
   • Failure to treat all close contacts simultaneously
   • Insufficient contact time with medication
   • Premature washing off of medication

2. Follow-up considerations:

   • Pruritus may persist for several weeks after successful treatment 1
   • Evaluate after 1 week if symptoms persist 1
   • Retreatment is only necessary if living mites are detected 2

3. Application technique:

   • Some evidence suggests that applying permethrin as cold cream (refrigerated) may improve efficacy 7
   • For difficult cases, two applications of permethrin with a one-week interval has shown higher efficacy (96.9%) 7, 4

4. Scalp treatment:

   • While scabies rarely affects the scalp in adults, treatment failures have been documented when the head/scalp is not treated 3
   • Consider scalp-to-toes application in treatment-resistant cases, especially in the elderly 3