Therapy of scabies and pediculosis: Potential and pitfalls

INTRODUCTION A great pitfall for scabies and pediculosis therapeutic studies to date is that primary and secondary study outcomes are indirectly assessed (presence or absence of live parasites, including eggs, determined by gross clinical inspection) and data timepoints are nonstandardized (highly variable) relative to time of therapeutic application. Certainly, kill times and kill rates are rarely determined or reported. Indeed, meta-analyses of randomized, controlled clinical trials for these parasitoses are scarce and, by nature, analyses are based on highly variable assessment methodology and data collection, followed by highly variable interpretation and reporting.(1, 2) Utilization of high-resolution, high-magnification videodermatoscopy (VD) in establishing highly definitive and precise quantitative data products used in the treatment of scabies and pediculosis provides enormous advantages in the quest to establish reproducible quantitative methodology for efficacy studies in these parasitoses.(3-6) Unfortunately, determination of the risk-benefit ratio for reported treatments does not involve uniform or precise methodology such as VD and, as a result, subjective weighing of literature reports is used to determine efficacy, and, subsequently, benefit-risk categorization. Clearly, standard methods such as VD allow for uniform data and, ultimately, uniform comparison and categorization of efficacy.