Scabies Treatment
Permethrin 5% cream is the first-line treatment for uncomplicated scabies, applied from the neck down for 8-14 hours, with oral ivermectin (200 μg/kg, repeated in 2 weeks) as an equally effective alternative for most patients. 1, 2
First-Line Treatment Options
Topical Permethrin 5% Cream
- Apply to all areas of the body from the neck down and wash off after 8-14 hours 1, 2
- One application is generally curative in most cases 2
- Preferred for pregnant/lactating women, infants, and young children due to superior safety profile 1, 2
- Safe and effective in children ≥2 months of age 3
Oral Ivermectin
- 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 <15 kg due to neurotoxicity risk 2
- Avoid in pregnant/lactating women due to limited safety data 2
- No dosage adjustment needed for renal impairment 1
Special Populations
Infants and Young Children
- Use permethrin 5% cream exclusively for infants ≥2 months old 2, 3
- Do not use ivermectin in children <15 kg 2
- Avoid lindane in children <10 years due to neurotoxicity risk 1, 2
Pregnant and Lactating Women
- Permethrin is the only recommended treatment 1, 2
- Ivermectin should be avoided due to insufficient safety data 2
- Consider temporarily discontinuing nursing or withholding permethrin while breastfeeding given animal tumorigenicity data 3
Crusted (Norwegian) Scabies
Requires aggressive combination therapy due to massive mite burden (thousands to millions of mites). 1
Treatment Protocol
- Topical permethrin 5% cream applied daily for 7 days, then twice weekly until cure 1
- PLUS oral ivermectin 200 μg/kg on days 1,2,8,9, and 15 1, 2
- The multiple-dose ivermectin schedule addresses limited ovicidal activity and massive mite burden 1
Critical Pitfalls to Avoid
- Never use single-application permethrin as recommended for ordinary scabies—this will fail 1
- Do not skip the oral ivermectin component—topical therapy alone is insufficient given mite burden and thick crusts 1
- Avoid lindane entirely in this population due to immunocompromised/debilitated status and neurotoxicity risk 1
Alternative Treatments (When First-Line Options Unavailable)
- Lindane 1%: Apply for 8 hours, but less effective than permethrin 1
- Sulfur 6% ointment: Apply for 3 consecutive nights 1
- Crotamiton 10%: Significantly less effective than permethrin (13% vs 30% cure at 2 weeks in children) 4
Contact and Environmental Management
Contact Tracing and Treatment
- Examine and treat ALL persons with sexual, close personal, or household contact within the preceding month 1, 2
- Treat contacts simultaneously even if asymptomatic 2
- Failure to treat contacts simultaneously is the most common cause of treatment failure 1
Environmental Decontamination
- Machine wash/dry bedding and clothing using hot cycle, or dry clean 1
- Alternatively, remove items from body contact for at least 72 hours 1
- Fumigation of living areas is unnecessary 1
Follow-Up and Persistent Symptoms
Expected Post-Treatment Course
- Rash and pruritus may persist for up to 2 weeks after successful treatment—this does NOT indicate treatment failure 1, 2
- Approximately 75% of patients with pruritus at 2 weeks will have resolution by 4 weeks 3
When to Retreat
- Consider retreatment only after 2 weeks if symptoms persist AND live mites are observed 1, 2
- Reasons for persistent symptoms include:
Critical Treatment Pitfalls
Application Errors
- Failure to apply permethrin to all critical areas including under fingernails and to the edge of all body orifices 1
- Not applying from neck down to entire body surface 1
- Using lindane after bathing increases absorption and toxicity risk 1
Medication Errors
- Not repeating ivermectin dose at 2 weeks is essential for complete eradication 1
- Expecting immediate symptom resolution leads to unnecessary retreatment 1