Prevalence of scratching during examination among patients with scabies and among patients with other pruritic dermatoses.

BACKGROUND Scabies is a parasitic skin disease. Its clinical diagnosis may be challenging. METHODS In a prospective observational study, we enrolled all consecutive patients ≥16 years of age with a presumptive diagnosis of scabies and all patients ≥16 years of age with a diffuse itchy dermatosis lasting for more than 1 week. We investigated whether patients with scabies were more prone to scratch themselves during the consultation than patients with other pruritic dermatoses. RESULTS We observed that a significant proportion of patients (25/62, 40%) with scabies had to scratch while talking or being examined. This clinical sign was less frequently noticed in patients with pruritic dermatoses of other origins (26/196, 13%) (P < 0.001). CONCLUSIONS The observation of a patient scratching himself during the consultation should prompt serious consideration of scabies. This easily observable clinical sign may be especially useful in low-resource settings, where scabies is known to be very prevalent.