Scabies: (Human Itch Mite)

Presentation

Patients present for evaluation due to inability to sleep as a result of intense itching. Severe pruritus, which is the hallmark of this disease, is intensified at night for unclear reasons. These patients have skin lesions that include mite burrows, which appear as short (about 2–3 mm in length), elevated, gray, threadlike, serpiginous tracks. A small papule or vesicle may appear at the end of the burrow or may occur independently ( Fig. 179.1 ). These papules and burrows are chiefly found in the interdigital web spaces ( Fig. 179.2 ), as well as on the volar aspects of the wrists, axillae, olecranon area, nipples, waistline, genitalia, and gluteal cleft ( Fig. 179.3 ). Nipple pruritus in females is a useful historical clue. Pruritic erythematous papules on the glans penis are characteristics of scabies infestation in males ( Fig. 179.4 ). The head and neck are usually spared, but scabies lesions can occur anywhere on the body ( Fig. 179.5 ), including the face and scalp. Infants and young children may also have palm and sole involvement with vesicular and pustular lesions. Secondary bacterial infection is sometimes present. Scabies in the elderly may be difficult to diagnose because the cutaneous lesions are often very subtle.