Efficacy of combination therapy with oral Ivermectin and topical permethrin versus permethrin monotherapy in pediatric patients with persistent scabies: a propensity score-adjusted observational study.

backgroundScabies is a highly contagious parasitic infestation that disproportionately affects children in resource-limited settings. Topical 5% permethrin is first-line therapy, but effectiveness is limited by suboptimal application, rapid reinfestation, and emerging resistance. Adding oral ivermectin to permethrin has shown promise in small series, yet its cost-28-37% of the 2022 minimum wage in Türkiye before generics and still 5-7% after-puts it beyond reach for many families, with similar gaps in other low-income countries. We conducted a propensity-score-adjusted study comparing ivermectin + permethrin versus permethrin alone in children, aiming to quantify clinical benefit, safety and generate evidence to guide policies enhancing financial access to effective therapy.

methodsFrom January 2022 to January 2024, we enrolled 230 children (< 18 years; >15 kg) whose scabies persisted after ≥ 1 permethrin course. After cost counselling, families chose either combination therapy (oral ivermectin at 200 µg/kg on Day 0 and 14 plus permethrin) or continued permethrin monotheraphy. Baseline demographic, socioeconomic and clinical variables were used to derive a propensity score adjusting for non-random treatment allocation. Lesion count and pruritus scale were assessed weekly for 4 weeks then monthly for 3 months; recurrences and adverse events (AEs) were recorded at each visit.

resultsCombination therapy significantly accelerated symptom relief (time to 50% pruritus reduction: 7.2 ± 1.8 vs. 9.8 ± 2.1 days; p < 0.001) and yielded higher Week 2/3/4 cure rates (55.0%/75.0%/83.8% vs. 30.0%/55.3%/66.0%). Three-month recurrence was lower with combination therapy (7.1% vs. 17.1%; p = 0.05). Mild, self-limiting adverse events were more common in the combination arm (14.3% vs. 4.3%; p = 0.04), predominantly transient itch flare and headache; no moderate, serious, or treatment-limiting events occurred.

conclusionsIn this study adding two oral doses of ivermectin to standard permethrin shortened symptom resolution time, raised cure rates, and halved recurrences, with only modest rise in transient mild AEs. Future randomised trials should couple efficacy with cost-effectiveness analyses and evaluate policy options-generic licensure, unit-tablet dispensing, and insurance reimbursement-to ensure equitable access to this regimen. TRIAL REGISTRIATION: Clinical trial number not applicable.