New insights in pediculosis and scabies

Abstract

Despite the use of powerful insecticides and the prodigious efforts of parents and health providers, successful control of head louse infestations remains unattainable in most countries. The main reasons for ineffective control of head lice are sale of ineffective pediculicides, incorrect use of pediculicides, use of alternative remedies and methods for which efficacy has not been clinically proven, development of resistance to insecticides, improper attention to possible fomite transmission, difficulty in diagnosing head lice infestations and embarrassment and social stigma that prevents reporting. Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity response (type IV immune reaction) to infestation of the skin by the mite Sarcoptes scabiei. This article reviews the biology of the mite, the clinical aspects and diagnosis of scabies infestations, as well as the treatment of choice with permethrin 5% dermal cream and the use of scabicides based on other chemical substances. Reports of scabies mites resistant to ivermectin and permethrin indicate that alternative treatment modalities should be sought and investigated.