Guideline for the diagnosis and treatment of scabies in Japan (third edition)

Abstract

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.

Diagnostic Accuracy of Dermoscopy for Scabies

“…DS is usually performed with a polarized light source or by the application of an immersion liquid (oil or water) to the skin, which helps to eliminate light reflection [11]. Pigmented structures and the vasculature of the skin surface to the superficial dermis can be inspected using DS; therefore, it is effective for identifying scabies mites and burrows in vivo [5][6][7][11][12][13].…”

“…Hands, arms, and the abdomen had the highest positivity rates for mites (P < 0.001). These areas with tender skin are the most pre-disposed to infection by scabies mites and should be prioritized for detection to improve the positivity rates [5].…”

“…It usually presents with herpes, papulovesicles, nodules, and intense pruritus at night, which cause pain and disturbed sleep in the affected individuals. Accurate and prompt diagnosis of scabies, along with appropriate isolation and treatment, is crucial to preventing its spread [5]. At present, the diagnosis is primarily based on clinical manifestations and microscopic examination.…”

Crusted scabies; a 2-year prospective study from the Northern Territory of Australia

“…We documented the actual therapy received for each patient, including noting the total number of doses of ivermectin. The NT guidelines for crusted scabies have been used internationally [2,9].…”

Treatment practices in the management of scabies in infants younger than two months

“…10,11 However, the Centers for Disease Control and Prevention (CDC) recommend precipitated sulfur which acts as a keratolytic and a scabicide through its conversion to hydrogen sulfide and pentathion. 6,8 Formal efficacy and safety data for precipitated sulfur in this age-group are lacking, but it is recommended in the literature. 12 Outside the United States, benzyl benzoate is commonly used.…”