Scabies is the name of a microscopic, parasitic mite, but it is also the term used for the intensely itchy, pimple-like rash that this mite causes. When scabies mites tunnel under human skin to lay their eggs, they leave behind a network of raised burrows that causes severe itching, or pruritis. Scabies affects people of all ages, genders and social classes. Poor personal hygiene does not cause scabies. The parasitic mite is transmitted in a number of ways.
Close Physical Contact
People who share housing or are in close, prolonged contact on a regular basis may transmit the mite to each other. Brief, casual contact, such as brushing against another person on a bus or shaking hands, does not typically cause scabies. Scabies mites can live for up to 72 hours without a human host.
Sharing Personal Items
Clothing, towels, bedding and other personal items may hold scabies mites after the items have been in contact with a human host. Clothing, bedding or towels used by persons infested with scabies within the three days before they started treatment should be washed in hot water and dried in a hot dryer, sealed in a plastic bag for 72 hours or dry-cleaned.
Scabies mites often infest the groin area, and people who are intimately involved may transmit the mites to each other during sexual activity.
Living in an Institutional Setting
Scabies is common in institutional facilities such as hospitals and nursing homes, where people live in close proximity with each other.
Crusted Norwegian Scabies
Crusted Norwegian scabies is an aggressive, highly contagious form of this condition that occurs in the elderly, in people whose immune systems are compromised by illness and in people who are immobilized by paralysis or mental debility. This form of scabies leaves sores covered with thick crusts that may contain millions of mites. In these cases, casual contact with furniture or a personal item that the host has used may be enough to transmit scabies.