Scabies Treatment
Permethrin 5% cream applied from the neck down (including scalp in infants) for 8-14 hours is the first-line treatment for uncomplicated scabies, with one application generally being curative. 1, 2, 3
First-Line Treatment Options
Topical Permethrin (Preferred)
- Apply permethrin 5% cream to all areas of the body from the neck down and wash off after 8-14 hours 1, 2, 3
- For infants, young children, and geriatric patients, also treat the scalp, hairline, neck, temple, and forehead 1, 2, 3
- Approximately 30 grams is sufficient for an average adult 3
- One application is generally curative 3
- Permethrin is particularly recommended for pregnant women, lactating women, infants, and young children due to its safety profile 1, 2
Oral Ivermectin (Alternative First-Line)
- Dose: 200 μg/kg, repeated in 2 weeks 1, 2
- Must be taken with food to increase bioavailability and epidermal penetration 1
- Contraindicated in children weighing less than 15 kg due to neurotoxicity risk 2
- Avoid in pregnant and lactating women due to limited safety data 2
- No dosage adjustments needed for renal impairment 1
Special Population Considerations
Pregnant/Lactating Women
- Use permethrin exclusively—avoid ivermectin 2
Infants and Young Children
- Permethrin is preferred; apply to scalp, temple, and forehead in addition to body 2, 3
- Do not use ivermectin in children <15 kg or infants <2 months old 2
Crusted (Norwegian) Scabies
- Requires aggressive combination therapy due to massive mite burden (thousands to millions of mites) 1
- Regimen: Topical permethrin 5% cream applied daily for 7 days, then twice weekly until cure, PLUS oral ivermectin 200 μg/kg on days 1,2,8,9, and 15 1, 2
- Single-application permethrin or single-dose ivermectin alone will fail 1
- This population is often immunocompromised, requiring closer monitoring 1
Contact and Environmental Management
Contact Tracing and Treatment
- Examine and treat ALL persons with sexual, close personal, or household contact within the preceding month, even if asymptomatic 1, 2
- Failure to treat contacts simultaneously is the most common cause of treatment failure 1
Environmental Decontamination
- Machine wash and dry bedding, clothing, and towels using hot cycles, or dry clean 1, 2
- Alternatively, remove items from body contact for at least 72 hours (mites cannot survive off the host beyond this period) 1
- Fumigation of living areas is unnecessary 1, 2
Follow-Up and Persistent Symptoms
Expected Post-Treatment Course
- Rash and pruritus may persist for up to 2 weeks after successful treatment—this is NOT treatment failure 1, 2
- Persistent symptoms are due to hypersensitivity reaction to dead mites and debris 1
When to Retreat
- Consider retreatment only after 2 weeks if symptoms persist AND live mites are observed 1, 2, 3
- Demonstrable living mites after 14 days indicate retreatment is necessary 3
Alternative Treatments (Less Preferred)
Lindane 1%
- Avoid in children <10 years, pregnant/lactating women, and persons with extensive dermatitis due to neurotoxicity risk 1, 2
- Never use after bathing, as this increases absorption and toxicity 1
- Less effective than permethrin 1
Sulfur 6% Ointment
- Alternative option when permethrin and ivermectin are contraindicated 1
Critical Pitfalls to Avoid
Application Errors
- Failure to apply permethrin to all body areas, including under nails and to the edge of all body orifices 1
- Not treating the scalp and face in infants, young children, and geriatric patients 1, 3
Treatment Protocol Errors
- Not repeating ivermectin dose at 2 weeks—essential for complete eradication 1
- Expecting immediate symptom resolution—pruritus can persist 2 weeks post-treatment 1, 2
Contact Management Errors
- Failure to treat all close contacts simultaneously leads to reinfection 1
- Inadequate environmental decontamination of bedding and clothing 1