Ivermectin safety in infants and children under 15 kg treated for scabies: a multicentric observational study

Summary Background Scabies is a frequent condition seen in infants and children. Only topical treatments have been approved in infants, but some of them are poorly tolerated. Oral ivermectin is approved for the treatment of scabies in several countries, but its use in infants and children weighing < 15 kg is off label. Objectives To assess the safety of ivermectin in infants and young children, and to collect data on ivermectin efficacy in these age groups. Methods This study was performed in the dermatology and paediatric dermatology departments of 28 French centres between July 2012 and November 2015. Physicians treating an infant or child weighing < 15 kg for scabies with oral ivermectin were asked to send back a completed standardized and anonymous questionnaire, and the data were analysed. Results Data were collected on 170 infants and children aged 1–64 months, with a body weight of 4–14·5 kg, who were treated with oral ivermectin. The mean dose received was 223 μg kg–1 and 89% of the patients received a systematic second dose. Concomitant topical treatment was administered to 73% of patients. Adverse events were reported in seven patients (4%) and were not severe. At the follow‐up visit, 139 (85%) patients had achieved healing. Factors significantly associated with healing were an ivermectin dose > 200 μg kg–1 (P < 0·001), and a delay between those two doses of < 10 days (P = 0·025). Conclusions Our findings suggest the safety and efficacy of ivermectin for the treatment of scabies in infants and young children. What's already known about this topic? Scabies is a frequent condition in small children and infants, but the therapeutic options are limited. Ivermectin has been approved for the treatment of scabies in adults and children > 15 kg, but its use is off‐label in infants and children weighing < 15 kg. Safety data on the use of ivermectin in children weighing < 15 kg are limited. What does this study add? Of 170 infants and children weighing < 15 kg who were treated for scabies with oral ivermectin, there were only seven reported mild adverse events and no serious ones. Our results show that ivermectin is effective in treating scabies in 85% of patients. Efficacy is higher when the received dose exceeds 200 μg kg–1 and when the delay between the two doses is < 10 days. Respond to this article Linked Comment: Morris‐Jones. Br J Dermatol 2020; 182:835–836.