Crusted Scabies with Marked Eosinophilia in a Patient with Type 2 Diabetes Mellitus

Abstract

Crusted scabies, or Norwegian scabies, is an atypical and rare form of scabies. It is usually associated with immunocompromised conditions including diabetes mellitus and neurological impairments resulting in sensorial deficits and physical disability. The diagnosis of crusted scabies is often missed initially because of unfamiliarity with the disease, Misdiagnosis, delayed treatment, or inadequate isolation measures of this disease can lead to spreading of scabies infestation among family members and in institutions including nursing homes and hospitals. Eosinophilia is common in patients with crusted scabies. We report one case of crusted scabies in a patient with type 2 diabetes mellitus with poor glycemic control. He had severe disability related to multiple diabetic complications and mental degeneration. Diffusely psoriasiform and hyperkeratotic lesions and marked eosinophilia were noted. Microscopic examination of skin scrapings confirmed the diagnosis. Three nurses of our hospital had suffered from outbreak infections related to delayed diagnosis. More intense isolation precautions should be used than in other commonly seen infectious diseases spreading via contact routes. Severe pruritus and typical skin lesions in a patient with immunosuppression or neurological impairments raise the suspicion of crusted scabies, and eosinophilia, if appearing, is one of diagnostic clues.