A randomized controlled trial comparing 1% permethrin shampoo versus 5% permethrin lotion for treating scabies in adults

Abstract

Background & Objective: Scabies, caused by the mite Sarcoptes scabiei var. hominis, is a highly contagious condition with significant public health implications. Standard treatments for scabies can be expensive, particularly in economically disadvantaged areas. This study aimed to determine the efficacy of 1% permethrin shampoo compared to the standard 5% permethrin lotion in treating scabies, assessing Total Lesion Count (TLC), Skin Infection Rating Scale (SIRS), clinical response, adverse events, and treatment acceptability.

Methodology: This is an open-label, randomized clinical trial conducted in Barangay Malagutay, Zamboanga City, Philippines, involving 28 participants (14 per group). After dermatologic confirmation of diagnosis and a skin irritation test, participants were randomly assigned to receive either 5% permethrin lotion or 1% permethrin shampoo. Outcome measurements included Total Lesion Count (TLC) and SIRS, which evaluated erythema, crusting, purulence, itching, and pain. These were assessed on Days 0, 3, and 7. Clinical response, treatment acceptability, and adverse events were also monitored throughout the 7-day study period.

Results: Results showed both treatments were effective with comparable outcomes on Day 3. Improvement in lesions, SIRS-erythema, crusting, purulence, pain, and itching was observed for both groups from Day 0 to Day 7. No significant difference was noted between the groups (p > 0.05) on Day 3. Both 1% and 5% permethrin treatments showed complete symptom resolution by Day 7, achieving 100% treatment success with 1% permethrin shampoo and 93% with the 5% permethrin lotion.

Conclusion: 1% permethrin shampoo offers effective treatment for scabies, with comparable efficacy to 5% permethrin lotion.