Overview
Scabies is an itchy skin condition caused by a tiny parasite (mite) called
Sarcoptes scabiei that can live and multiply (infest) on skin. Scabies is passed between people by prolonged skin-to-skin contact. Scabies is extremely contagious and spreads rapidly in crowded conditions such as hospitals, nursing homes, child-care facilities, and other situations where people spend extended periods of time in close contact with each other.
The itchy rash of scabies develops when a pregnant female mite burrows into the outer surface (superficial) skin and lays eggs. The human immune system is highly sensitive to the presence of the mite and produces a massive allergic response, which causes intense itching. Although a typical infection includes only 10–20 mites, people are so sensitive to the mite that hundreds of itchy skin lesions are created. Without treatment, the condition will not usually improve.