Efficacy of topical Ivermectin in controlling human Demodex infestation: Evidence from systematic review and meta-analysis

Abstract

Background: Demodex mites are usually harmless but can contribute to inflammatory skin conditions like rosacea, blepharitis, and demodicosis. While new therapies like lotilaner, niclosamide, and berberine show promise against D. folliculorum, ivermectin remains widely used for its strong antiparasitic and anti-inflammatory effects. However, the direct effectiveness of ivermectin in reducing Demodex mite density in associated skin diseases is not fully quantified. Materials and methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. PubMed, Scopus, the Cochrane Library, and Google Scholar were searched for studies published between December 2014 and December 2024. Eligible studies have assessed the effect of topical ivermectin on Demodex mite number or density using standardized diagnostic methods. Risk of bias was evaluated using the Risk of Bias Assessment Tool for Non-randomized Studies (RoBANS) and the Cochrane Risk of Bias Tool. Data were pooled using a random-effects model where appropriate. Results: A total of 2344 studies were identified, with five studies (n = 180 participants) meeting the inclusion criteria. All studies reported significant reductions in Demodex mite count or density after daily application of topical ivermectin 1 %. Meta-analyses demonstrated a mean reduction of 70.01 mites/cm² and an 80 % decrease in Demodex-positive (≥5 D/cm²) rates. A 16-week treatment duration was associated with a notable reduction, with effects sustained for up to 12 weeks post-treatment. Only mild, localized adverse events were reported, with no systemic side effects observed. Conclusion: Topical ivermectin is effective and well-tolerated for reducing the number and density of Demodex mites. A 16-week treatment course significantly decreases mite burden and improves clinical outcomes with minimal adverse events. However, the potential for mite repopulation after treatment underscores the importance of ongoing monitoring. Study heterogeneity and the limited number of included trials warrant cautious interpretation of the findings.