Efficacy and Safety of Topical Permethrin, Oral Ivermectin Versus Combined Therapy in Scabies: A Randomized Controlled, Single Blind, Cross-sectional Study in Bangladesh

Abstract

Background: Scabies is an intensely transmissible ectoparasitic skin infestation that continues to cause significant morbidity, particularly in populations with limited healthcare resources. Although topical permethrin 5% remains the standard first-line treatment, its clinical success is often reduced due to incorrect application techniques, frequent reinfestation, and the growing concern of therapeutic resistance. Recent evidence suggests that incorporating oral ivermectin alongside topical permethrin may enhance treatment outcomes with a promising future. Aims: The present study was undertaken to comparatively assess the efficacy and safety of permethrin and ivermectin administered independently and in combination among patients diagnosed with scabies. Materials and Methods: The study was carried out in several private medical clinics located in Gazipur, Bangladesh, over six months. A total of 150 patients aged between 18 and 60 years with a confirmed diagnosis of scabies were enrolled and randomly divided into three treatment arms. Participants in Group A were treated with topical 5% permethrin cream, Group B received a single oral dose of ivermectin at 200 μg/kg body weight, while Group C was administered both permethrin and ivermectin concurrently. Clinical assessments were performed weekly over a four-week follow-up period. In instances where complete resolution was not observed, the assigned therapeutic regimen was repeated once after the first week. Treatment effectiveness and the occurrence of adverse drug reactions were systematically evaluated throughout the study duration. Results: Successful clinical response was achieved in 70% of patients treated with permethrin alone, 66% of those receiving ivermectin monotherapy, and 88% of patients managed with combination therapy. Statistical analysis demonstrated significant superiority of the combined regimen compared to either monotherapy. At the completion of the first and fourth weeks, cure rates were recorded as 70% and 92% in Group A, 66% and 86% in Group B, and 88% and 97% in Group C, respectively, further highlighting the enhanced effectiveness of the dual-drug approach. Adverse effects were reported in 6% of patients in the permethrin group, 4% in the ivermectin group, and 8% in the combination group, which was higher than their single use; however, these events were mild in nature, transient, and did not reach statistical significance. Conclusion: The findings of this study indicate that the combined use of topical permethrin and oral ivermectin offers superior therapeutic efficacy compared with either agent used alone in the management of scabies, despite a marginally higher incidence of mild adverse effects.