Current treatments for scabies

Scabies is a frequent interhuman ectoparasitic infection. Several treatments are available worldwide. There are local treatments: synthetic pyrethrins, benzyl benzoate, lindane, crotamiton. Recently a few studies were published concerning ivermectin, systemic antiparasitic agent use in onchocercosis treatment. We reviewed the literature with an evidence-based medicine method. We attempt to answer two questions in particular: what is the treatment of choice for common scabies in a patient otherwise in good health? What is the role of systemic ivermectin? We also report specific situations. Among local treatments, studies are heterogeneous according to products, countries, group of treated patients, with or without contact subjects, and the method of treatment application. There are very few high proof-level controlled studies. In France, a combination of benzyl benzoate 10% and sulfiram 2% is used most, according to professional consensus. The most studied product is the cream permethrin 5%, available in the USA and UK. Its efficacy seems slightly superior to lindane and less toxic. It is more efficient than crotamiton. There is no study comparing benzyl benzoate and permethrin. Concerning systemic ivermectin, five controlled studies showed its efficiency in common scabies. But its relative efficiency over local treatment has not been established. A few open studies showed its efficacy in institutional epidemic, profuse scabies and in HIV-positive patients. Local treatment of choice in common scabies remains to be determined among the four principal molecules. There is no study comparing permethrin or esdepallethrin to benzyl benzoate. In what cases should we prescribe crotamiton or lindane? Indication of ivermectin seems proved in common scabies and probably for HIV-positive patients. It remains to be determined if it should be prescribed in the first instance, be double or triple, be associated or not with local treatment. In case of keratotic scabies, ivermectin seems interesting with two applications within 1 week, and should be associated with local treatment (duration remains to be defined). Ivermectin is probably useful in institutional epidemic, and therapeutic attitude remains to be defined. Ivermectin seems to have little or no risk. Treatment must be adapted case-by-case, according to feasibility. It is still important to treat contacts, and modality of this treatment remains to be specified.