Crusted scabies

**Definition:** Crusted scabies results from unchecked proliferation of the human scabies mite in individuals who are unable to mount an adequate immune response to infestation. Extensive thick crusts containing vast numbers of mites form over the skin, particularly of the extremities. Because itching is usually absent, the diagnosis is frequently overlooked. Patients with crusted scabies may serve as the source for widespread outbreaks of scabies in institutions such as hospitals and care homes.