Pachyderma due to scabies

A 65-year-old white man with a history of multiple myeloma presented with thick, leathery, gray skin of the torso and extremities. Panel A shows the left axilla. The patient reported intense pruritus and thickening of his skin during the previous 6 months, despite treatment with oral and topical corticosteroids. Because of chronic immunosuppression due to his underlying malignant condition, a specimen obtained from scrapings of the skin was prepared and examined. It showed scabies mites, eggs, and scybala (fecal pellets) (Panel B), which confirmed a diagnosis of crusted scabies.

The patient was treated with oral ivermectin and topical permethrin, with noticeable improvement within 1 month; subsequently, the patient was lost to follow-up.
Crusted scabies is a rare variant of scabies and occurs most commonly in immunosuppressed patients.
It presents as: erythematous or gray hyperkeratotic patches or plaques that can resemble the hide of a pachyderm (elephant, rhinoceros, or hippopotamus); “pachyderma” refers to thick skin, like that of a pachyderm. Patients with crusted scabies have a very high burden of mites and are extremely infectious. Thus, a prompt diagnosis is needed to avoid transmission to others. No such transmission was documented in this case.