Scabies

Scabies (from Latin: scabere, "to scratch"), known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It has been classified by the WHO as a water-related disease. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching. The infection in animals (caused by different but related mite species) is called sarcoptic mange.