- Scabies is an infestation of the skin by the human itch mite (Sarcoptes scabiei var. hominis). The microscopic scabies mite burrows into the upper layer of the skin where it lives and lays its egg.
- Scabies can spread rapidly under crowded conditions where close body and skin contact is frequent.
What is crusted (Norwegian) scabies?
- Crusted scabies is a severe form of scabies that can occur in some persons who are immunocompromised (have a weak immune system), elderly, disabled, or debilitated. It is also called Norwegian scabies. Persons with crusted scabies have thick crusts of skin that contain large numbers of scabies mites and eggs
- Persons with crusted scabies are very contagious to other persons and can spread the infestation easily both by direct skin-to-skin contact and by contamination of items such as their clothing, bedding, and furniture.
- Persons with crusted scabies should receive quick and aggressive medical treatment for their infestation to prevent outbreaks of scabies.
Infestation is common, found worldwide, and affects people of all ethnic backgrounds and social classes. Because scabies spreads easily under crowded conditions where close body and skin contact is common, institutions such as nursing homes, extended-care facilities, childcare facilities, and prisons are often sites of scabies outbreaks. In addition, household members and sexual partners of infested people are also at high risk.
How is Scabies spread?
- Scabies usually is spread by direct, prolonged, skin-to-skin contact with a person who has scabies. Contact generally must be prolonged; a quick handshake or hug usually will not spread scabies.
- Scabies is spread easily to sexual partners and household members. Scabies in adults frequently is sexually acquired.
An infested person can spread scabies even if he or she has no symptoms.
Household pets and other animals do not spread the human form of scabies.
- Itching. Itching is caused by an allergic reaction to the proteins and feces of the mite. Severe itching, especially at night, is the earliest and most common symptom of scabies.
- Rash. A pimple-like itchy rash is common and may affect much of the body or be limited to common sites such as between the fingers, wrist, elbow, armpit, penis, nipple, waist, buttocks, and belt-line. The head, face, neck, palms, and soles are often infested in infants and very young children, but usually not in adults and older children.
- Burrows. Tiny burrows are sometimes seen on the skin. These are caused by the female scabies mite tunneling just beneath the surface of the skin. Burrows appear as tiny raised and crooked grayish-white or skin-colored lines on the skin surface. Because mites are often few in numbers, these burrows may be difficult to find.
People with crusted scabies may not show the usual signs and symptoms of scabies such as the characteristic rash or itching.
- Treatment is recommended for the infested person as well as all household members and sexual contacts, particularly those who have had prolonged direct skin-to-skin contact with the infested person within the preceding month. All people should be treated at the same time to prevent reinfestation.
- Products used to treat scabies are called scabicides and are available only with a doctor’s prescription. .
- When treating adults and older children, scabicide lotion or cream should be applied to all areas of the body from the neck down to the feet and toes. When treating infants and young children, scabicide lotion or cream should also be applied to their entire head and neck. The lotion or cream should be applied to a clean body and left on for the recommended time before washing it off.
- No “over-the-counter” (non-prescription) products have been tested and approved to treat scabies. Never use a scabicide intended for veterinary or agricultural use to treat humans.
- Itching may continue for several weeks after treatment even if all the mites and eggs are killed. If itching is still present more than two to four weeks after treatment or if new burrows or pimple-like rash lesions continue to appear, retreatment may be necessary.
- Skin sores that become infected should be treated with an appropriate antibiotic prescribed by a doctor.
An adult female mite can live up to a month on a person but will not survive for more than 48-72 hours away from the body. Fumigation of living areas is unnecessary. To prevent re-infestation and to prevent the mites from spreading to other people, take these steps:
- Clean all clothes and linen. Use hot, soapy water to wash all clothing, towels and bedding used at least two days before treatment. Dry with high heat. Dry clean items you can’t wash at home.
- Starve the mites. Consider placing items you can’t wash in a sealed plastic bag and leaving it in an out of-the-way place, such as in your garage, for a couple of weeks. Mites die if they don’t eat for a week.