Atypical crusted scabies.

Five cases of an atypical form of crusted (or Norwegian) scabies are described. Three cases occurred in patients who suffered from a malignant tumor, and two additional cases occurred in mentally retarded and physically debilitated patients. These cases should draw attention to the possibility of a scabietic infestation whenever a widespread, scaly, itchy dermatosis develops in a debilitated immunosuppressed patient.