From the Guidelines
Scabies treatment should prioritize combination therapy with both topical permethrin and oral ivermectin for crusted (Norwegian) scabies, as recommended by the 2015 sexually transmitted diseases treatment guidelines 1. This approach is crucial in managing the aggressive infestation that usually occurs in immunodeficient, debilitated, or malnourished persons. The treatment regimen should include a topical scabicide, either 5% topical benzyl benzoate or 5% topical permethrin cream, applied daily for 7 days and then twice weekly until discharge or cure, in combination with oral ivermectin 200 ug/kg on days 1,2,8,9, and 15 1.
Key considerations in scabies treatment include:
- Environmental decontamination to prevent reinfestation, as mites can survive 48-72 hours off the human body
- Simultaneous treatment of all household members and close contacts
- Proper application of medication to all skin areas to ensure treatment success
- Awareness of potential secondary bacterial infections requiring additional treatment with antibiotics
- Persistence of itching for 2-4 weeks after successful treatment due to hypersensitivity reactions to dead mites 1
In cases where treatment failure occurs, retreatment 2 weeks after the initial treatment regimen can be considered, with an alternative regimen recommended for those who do not respond initially to the recommended treatment 1. It is essential to prioritize combination therapy and environmental decontamination to minimize the risk of reinfestation and ensure effective treatment of scabies.
From the FDA Drug Label
INDICATIONS AND USAGE Permethrin Cream, 5% is indicated for the treatment of infestation with Sarcoptes scabiei (scabies). INDICATIONS AND USAGE: For eradication of scabies ( Sarcoptes scabiei) and for symptomatic treatment of pruritic skin. The latest review of scabies treatment options include:
- Permethrin cream, 5% for the treatment of scabies infestation 2
- Crotamiton for the eradication of scabies and symptomatic treatment of pruritic skin 3
From the Research
Treatment Options for Scabies
- Topical permethrin 5% cream is the first-line treatment for scabies, as recommended by several studies 4, 5, 6.
- Oral ivermectin is also a first-line therapeutic alternative, which can be administered during lactation and is safe in children >15kg 5.
- The combination of permethrin 5% cream and fusidic acid 2% cream is more effective than treating with only 5% permethrin for impetiginized scabies 4.
- Topical lindane and crotamiton are inferior to permethrin but appear equivalent to each other and benzyl benzoate, sulfur, and natural synergized pyrethrins 6.
Efficacy of Treatment Options
- The efficacy of permethrin 5% cream and fusidic acid 2% cream was higher than permethrin 5% and placebo in a double-blind, randomized clinical trial 4.
- Oral ivermectin may reduce the prevalence of scabies at one year in populations with endemic disease more than topical permethrin 6.
- Two applications of topical ivermectin provided a cure rate of 64.7% at the 2-week follow-up, which increased to 82.3% at the 4-week follow-up after repeating the treatment 7.
Safety and Side Effects
- Permethrin 5% cream and fusidic acid 2% cream had minor adverse effects such as itch and heat, which occurred temporarily 4.
- Ivermectin was quite safe in the cases studied, with no significant side effects reported 7.
- Topical permethrin 5% is recommended as first-line treatment and can be indicated during pregnancy and lactation, and appears to be safe in children <2 months 5.