What is Norwegian or crusted scabies?
Norwegian scabies, or crusted scabies, is a severe form of scabies first described in Norway. Crusted scabies almost always affects people with a compromised immune system and is observed most frequently in the elderly, those who are mentally or physically disabled, and in patients with AIDS, lymphoma, or other conditions that decrease the effectiveness of the immune response. Due to the poor function of the immune system, an individual may become infested with hundreds of thousands of the mites. The lesions of this distinctive form of scabies are extensive and may spread all over the body. The elbows, knees, palms, scalp, and soles of the feet are most commonly the original sites of involvement, and the scaly areas eventually take on a wart-like appearance. The fingernails can be thickened and discolored. Interestingly, itching may be minimal or absent in this form of scabies. A particular danger of crusted scabies is that these lesions often predispose to the development of secondary