Unlike the classical variant of scabies, crusted scabies does not usually present with severe itching. This is particularly remarkable, given the high mite burden in these cases! The lack of severe itching is related to the depressed immunity of infected individuals. People with crusted scabies are infected with the same mite as people with the classical variant of scabies, but are usually immunocompromised or severely debilitated. Without the host immune response to keep the infection in check, the mites proliferate and produce large crusted lesions that are packed with eggs, mites and fecal pellets.
The predominant finding in this case is the fecal pellets (scybala). Mixed among the scybala are occasional mites which allow for definitive identification: