[Therapeutic failure in scabies: An observational study]. / Gales en échec de traitement : étude observationnelle.

ABSTRACT

BACKGROUND: Several sources suggest an escalation of scabies in France. AIM: To describe a population of patients continuing to present with scabies despite multiple treatments in order to identify factors associated with persistence of infection. PATIENTS AND METHODS: A descriptive cross-sectional study in adults and children consulting for persistent scabies despite at least one previous treatment. A standardized questionnaire explored potential sources of treatment failure. RESULTS: Thirty-one patients were analyzed. Initial symptoms were noted to have started between two and 52 weeks earlier (mean 19 weeks). The mean number of prior consultations with a general practitioner was 3.1 (0-10) and 1.7 with a dermatologist (0-7). The mean number of patients per household was 3.5 (1-9). At least one dose of oral ivermectin (maximum of 6 doses per household) was prescribed for 84 % of patients (29 % of whom were not fasted at the time). Further, 74 % of patients received at least one local application of esdepallethrin and piperonyl butoxide (maximum 5 courses), four received benzyl benzoate and two received permethrin; however, 58 % did not reapply the substance after hand washing. All households bought the prescribed treatments despite the costs. Close contacts of patients were treated in 58 % of households. Decontamination of bedding and clothing was carried out properly in 90 % of households. DISCUSSION: Persistence of infection appears to be linked to (1) insufficient treatment of close contacts; (2) absence of a second treatment between days 7 and 14; (3) insufficient efficacy of the available treatments, doubtless due to multiple factors (intrinsic resistance of Sarcoptes, failure to repeat treatment, poor explanation of methods for dosing and application, and oral intake of treatments). Access to non-reimbursed treatments was not identified as a problem and decontamination of bedding and clothing was correctly performed in most cases. CONCLUSION: Though certain fundamental aspects of scabies treatment must be better known, longer consultations and provision of efficacious treatments are also a priority.