Treatment Protocol for Resistant Scabies Cases
For resistant scabies cases, combination therapy with daily topical 5% permethrin cream plus oral ivermectin 200 μg/kg on days 1,2,8,9, and 15 is the recommended treatment approach. 1, 2
First-Line Treatment Failure Assessment
Before initiating treatment for resistant cases, confirm true treatment failure:
- Verify that initial treatment was properly applied (covering entire body from neck down, left on for 8-14 hours) 3
- Ensure all close contacts were treated simultaneously 1
- Rule out reinfection from untreated contacts or fomites 1
- Consider cross-reactivity with other household mites as a cause of persistent symptoms 1
- Remember that rash and pruritus may persist for up to 2 weeks after successful treatment 1, 2
Treatment Protocol for Resistant Cases
For Uncomplicated Resistant Scabies:
- Repeat 5% permethrin cream application with meticulous attention to proper application technique 1, 3
- Add oral ivermectin 200 μg/kg, taken with food to increase bioavailability 1
- Repeat ivermectin dose after 2 weeks 1, 2
- Ensure all close contacts are treated simultaneously 1, 2
For Crusted (Norwegian) Scabies:
- Implement intensive combination therapy: 1, 2
- Topical 5% permethrin cream applied daily for 7 days, then twice weekly until cure
- Oral ivermectin 200 μg/kg on days 1,2,8,9, and 15
- Consider more frequent monitoring for immunocompromised patients 1
Alternative Treatments for Resistant Cases
If permethrin and ivermectin combination fails:
- Consider crotamiton lotion, applied for two consecutive days and washed off 48 hours after the last application 4
- Sulfur 6% ointment is an alternative option, particularly when cost is a concern 5
- Avoid lindane due to risk of neurotoxicity, especially in children <10 years, pregnant women, and those with extensive dermatitis 1, 2
Environmental Management
- Decontaminate bedding and clothing by machine washing/drying using hot cycle, dry cleaning, or removing from body contact for at least 72 hours 1
- Ensure all household members and close contacts are treated simultaneously, regardless of symptoms 1, 5
- Fumigation of living areas is unnecessary 1
Special Populations
- For pregnant or lactating women: Use permethrin as the preferred treatment 2
- For children: Use permethrin for all ages; avoid ivermectin in children weighing less than 15 kg 2
- For immunocompromised patients: Use combination therapy and monitor more closely 1, 6
Follow-Up and Monitoring
- Evaluate for clinical improvement at 1,2, and 4 weeks after treatment 7, 8
- Retreatment is indicated if living mites are observed after 14 days 1, 3
- Persistent pruritus alone is rarely a sign of treatment failure 3
Common Pitfalls to Avoid
- Inadequate application of topical treatments (not covering all affected areas) 1
- Failure to treat all close contacts simultaneously 1, 9
- Not repeating ivermectin dose after 2 weeks 1
- Using lindane after bathing or in contraindicated populations 1
- Expecting immediate resolution of symptoms (may take up to 2 weeks) 1, 2