TOPLINE:

A small, randomized trial found that a higher dose of oral ivermectin (400 μg/kg) combined with 5% permethrin cream was not superior to the standard dose (200 μg/kg) in adults with severe scabies.

METHODOLOGY:

• Researchers conducted a blinded, randomized trial of 132 adults with confirmed severe scabies (profuse or crusted) between October 2017 and January 2025 in France.
• Participants were randomly assigned to receive oral ivermectin 400 μg/kg (higher-dose group; median age, 65.5 years; 53% women) or 200 μg/kg (standard-dose group; median age, 68 years; 43% women) on days 0, 7, and 14.
• Both groups applied 5% permethrin cream from head to toe on days 0 and 7, leaving it on for 8 hours overnight, and used daily emollient cream, with keratolytic agents permitted for crusted scabies.
• The primary end point was cure of severe scabies, defined as no mites and mite-related products on parasitologic or dermoscopic assessment on days 18 and 21, and no active clinical lesions noted on physical exam on day 28. The secondary endpoint was incidence of adverse events.

TAKEAWAY:

• Overall, the cure rate was not significantly different between the higher-dose group and the standard-dose group (75% vs 82%; odds ratio for cure, 0.64; 95% CI, 0.25-1.67).
• Subgroup analyses by scabies type did not identify any significant difference between the higher-dose and standard-dose groups among patients with crusted scabies or those with profuse scabies.
• Serious adverse events occurred in eight patients (three in the higher-dose group, including one thought to be “probably” related to the study drug; and five in the standard-dose group, including two thought to be “probably” related to the study drug). Two patients died in each group.
• Treatment-related cutaneous adverse events occurred in 14 patients in each group.

IN PRACTICE:

While the study did not provide evidence that higher-dose ivermectin was superior to the standard dose in patients with severe scabies, the authors wrote, “the results showed oral ivermectin taken at a dose of 200 μg/kg on days 0, 7, and 14, combined with 5% permethrin cream applied on days 0 and 7 and daily application of an emollient cream (with or without keratolytic agents), led to an 82% probability of cure of profuse and crusted scabies on day 28.”

SOURCE:

This study was co-led by Charlotte Bernigaud, MD, PhD, Department of Dermatology, Hôpital Henri-Mondor, Assistance Publique—Hôpitaux de Paris, and Giao Do‑Pham, MD, Department of Internal Medicine, Centre Hospitalier Intercommunal de Creteil, both in Créteil, France, and was published online on May 7 in The New England Journal of Medicine.

LIMITATIONS:

This study excluded patients with very severe crusted scabies, had incomplete follow-up for some patients, did not standardize diagnostic procedures, and lacked long-term outcome and transmission data.

DISCLOSURES:

This study received support from a grant provided by the French Ministry of Health and a grant provided by the French Society of Dermatology. Full disclosures are available in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.