Guideline for the diagnosis and treatment of scabies in Japan (third edition): Executive Committee of Guideline for the Diagnosis and Treatment of Scabies.

In the current work, we present our new guideline for the diagnosis and treatment of scabies which we, the Executive Committee convened by the Japanese Dermatological Association, developed to ensure proper diagnosis and treatment of scabies in Japan. Approval of phenothrin topical use under the National Health Insurance in August 2014 led to this action. Permethrin, a topical anti-scabietic medication belonging to the same pyrethroid group as phenothrin, is already in use worldwide. In this guideline, we introduce criteria for a proper diagnosis of scabies, treatment algorithm for common and crusted (hyperkeratotic) scabies, and prevention. The major change from our second edition is the treatment algorithm. As phenothrin is now available, the first-line therapy for common scabies is either topical phenothrin lotion or oral ivermectin. The second-line option for topical treatment is sulfur-containing ointments, crotamiton cream or benzyl benzoate lotion. γ-Benzene hexachloride ointment is no longer provided for clinical use. In an immunosuppressed patient, the treatment option is still the same, but with close follow up. If the symptoms persist, diagnosis and treatment must be reassessed. For hyperkeratotic scabies and nail scabies, removal of thick crust, cutting of nails and occlusive dressing are additionally required. The safety and effectiveness of combined treatment with topical and oral medications are not yet confirmed. Further assessment is needed. In addition to appropriate treatment, it is essential to educate patients and health-care workers and to conduct epidemiological studies to prevent further spread of the disease through effectively utilizing available resources including manpower, finance, logistics and time.