CLINICAL QUESTION

Is benzyl benzoate 25% or permethrin 5% more effective for the topical treatment of scabies in adolescents and adults?

BOTTOM LINE

Benzyl benzoate 25% was significantly more effective than permethrin 5% (number needed to treat = 2). It was also associated with more skin irritation, but this adverse event was generally mild to moderate and transient. (Level of Evidence = 1b)

SYNOPSIS

Researchers at one institution in Austria recruited 110 patients, 12 years and older, with dermoscopically diagnosed scabies. Patients with crusted scabies and those who had been treated for scabies in the previous 3 weeks were excluded. The patients' mean age was 28 years; 22% had been treated with topical permethrin, and 12% had been treated with oral ivermectin in the previous 3 months (the dosage of the latter was often judged to have been inadequate). The patients were randomized to receive topical benzyl benzoate 25% or permethrin 5% daily for 3 days in a double-blind fashion. The primary outcome of the absence of mites at 3 to 4 weeks after treatment occurred significantly more often in the benzyl benzoate group (87% vs. 27%; P < .001; number needed to treat = 2). However, mild to moderate burning or stinging was reported more often in the benzyl benzoate group (43% vs. 6%; P < .001; number needed to harm = 3). The skin irritation was short-lived and resolved spontaneously. Benzyl benzoate is widely available over the counter and is inexpensive.

Study design: Randomized controlled trial (double-blinded)

Funding source: Self-funded or unfunded

Allocation: Uncertain

Setting: Outpatient (any)

Reference: Meyersburg D, Hoellwerth M, Brandlmaier M, et al. Comparison of topical permethrin 5% vs. benzyl benzoate 25% treatment in scabies: a double-blinded randomized controlled trial. Br J Dermatol. 2024;190(4):486-491.

Editor’s Note: Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.