Permethrin Application for Scabies Treatment
Primary Recommendation
Apply permethrin 5% cream to all areas of the body from the neck down to the soles of the feet, leave on for 8-14 hours, then wash off thoroughly with soap and water. 1, 2, 3
Detailed Application Protocol
Pre-Application Preparation
- Trim fingernails short to reduce injury from scratching 2
- Ensure skin is completely dry before application 2
- Do not apply after bathing, as this can increase systemic absorption 1
Application Technique
- Massage the cream thoroughly into all skin surfaces from the neck down, including often-missed areas: 2, 3
- Between fingers and toes
- Under fingernails and toenails
- Wrists, elbows, and armpits
- Genitals and buttocks
- Soles of feet
- Use approximately 30 grams for an average adult 3
- Do not skip any areas from the neck down 2
Special Population Modifications
- Infants, young children, and elderly patients require treatment of the scalp, hairline, neck, temple, and forehead 2, 3
- Adults rarely need scalp treatment unless immunocompromised 3
Duration and Removal
- Leave cream on for 8-14 hours (overnight application is practical) 1, 2, 3
- Remove by thorough washing with soap and water (shower or bath) 2, 3
Treatment Frequency
One application is generally curative 2, 3. However:
- Retreatment is indicated only if living mites are visible after 14 days 2, 3
- If symptoms persist beyond 2 weeks with evidence of active infestation, a second application may be warranted 2
- Do not retreat based on persistent itching alone, as pruritus can persist up to 2 weeks after successful treatment 1, 2, 3
Concurrent Environmental Management
On the same day as treatment: 2
- Machine wash and dry all bedding, clothing, and towels using hot cycle 1, 2
- Alternatively, dry clean items or seal in plastic bags for at least 72 hours 1, 2
- Fumigation of the home is unnecessary 1, 2
Contact Management
All household members and sexual partners from the past month must be treated simultaneously, even if asymptomatic 1, 2. This is critical to prevent reinfection, which is a common cause of treatment failure 1.
Post-Treatment Expectations
- Itching may persist for up to 2 weeks after successful treatment 1, 2, 3
- This represents an allergic reaction to dead mites, not treatment failure 2
- Persistent pruritus alone is not an indication for retreatment 3
- Evaluate at 2 weeks post-treatment if symptoms persist to determine if retreatment is needed 1
Safety Profile
- Permethrin is safe for pregnant and breastfeeding women, infants, and young children 1, 2
- Minimal toxicity compared to alternatives like lindane 2
- Side effects are almost invariably mild 4
Common Pitfalls to Avoid
- Failure to treat all close contacts simultaneously leads to reinfection 1
- Inadequate application (missing body areas, insufficient quantity) 1
- Retreating based on persistent itching alone within 2 weeks 1, 3
- Using lindane after bathing or in contraindicated populations (children <10 years, pregnant/lactating women, extensive dermatitis) 1
Crusted Scabies Exception
For crusted (Norwegian) scabies, single-application permethrin will fail 1. These patients require combination therapy: topical permethrin applied daily for 7 days then twice weekly, plus oral ivermectin 200 μg/kg on days 1,2,8,9, and 15 1.