(A) A 79-year-old man with hyperkeratotic scabies for 4 years. The patient had been treated in his home with topical antiscabetic agents and oral ivermectin as well as extensive decontamination of his home on multiple occasions. Confluent hyperkeratotic plaques are seen on the back, buttocks, and legs. As many as five scabetic mites were seen on one microscope field (see inset). (B) A 50-year-old man with HIV and crusted scabies leading to powdery crusting of the toes.