Spot Diagnosis: A man presents to the Emergency Department with diffuse pruritus as well as the lesions that you notice below. You notice additional similar lesions on the bilateral hands, elbows, feet, and scalp. What is the diagnosis?
Answer: Crusted scabies. Scabies is an infestation of the skin by the mite Sarcoptes scabiei. Classic scabies typically manifests as an intensely pruritic eruption with a characteristic distribution. The sides and webs of the fingers, wrists, axillae, areolae, and genitalia are among the common sites of involvement. Crusted scabies, a less common variant that primarily occurs in the setting of reduced cellular immunity and is associated with a heavy mite burden, is characterized by thick scale, crusts, and fissures. The diagnosis of scabies is confirmed through the detection of scabies mites, eggs, or feces with microscopic examination.