Scabies is a skin condition caused by an infestation of the human itch mite called Sarcoptes scabiei. These microscopic mites burrow into the skin and produce symptoms of itching and rash. This mite is found worldwide and is transmitted by direct and prolonged skin-to-skin contact with a person who has scabies. Sexual contact is the most common way scabies is transmitted. Transmission can also occur from parents to children, particularly mother-to-infant. Without human contact, the mite can only survive about 48 to 72 hours, so it is unusual, though possible, for scabies to spread through infested bedding or furniture. However, once on a person, the mites can live up to two months. Mites survive longer in colder conditions with higher humidity. Once on a person, mites will burrow into the skin, and symptoms usually begin three to six weeks after infestation. Animals do not spread the same types of mites that cause human scabies, so it is impossible to catch scabies from a dog or cat.
Scabies usually begin with itching, which tends to be more severe at night, and a pimple-like rash. The rash can appear on any part of the body, but the most frequent sites are wrists, elbows, armpits, skin between the fingers and toes and around the nails, as well as on skin usually covered by clothing such as the buttocks, belt line, nipples, and penis. Infants and young children may have scabies rash on their head, face, neck, palms, and soles. In those with weakened immune systems, scabies rash may become crusted.
There are no approved over-the-counter treatments for scabies. A doctor must prescribe medication. The initial treatment for scabies may involve a topical cream, such as permethrin, which is applied directly to the skin, from the neck to the soles of the feet. It should be left on overnight and then washed off 8 to 14 hours later. Usually a second application after 1 to 2 weeks is advised. Other topical scabies therapies include Crotamiton cream or lotion, Lindane and Sulfur ointment. In some cases, oral Ivermectin may be used, particularly in cases where scabies encompass a large part of the body and is crusted. This particular medication is also often used in settings such as nursing homes where there may be widespread outbreaks. To get relief from the symptom of itching, some over-the-counter antihistamines such as diphenhydramine may help control the itch and enhance sleep.
As mentioned previously, scabies mites do not survive more than 72 hours without human contact. It is usually adequate to machine wash bed linens and clothing in hot water and dry on high heat, or have the items dry-cleaned. It is not necessary to have furniture or carpets cleaned as the mites will die off on their own in a few days without human contact.
Some additional ways you can treat scabies mites or prevent them from spreading include:
Scabies can often bear a resemblance to other skin conditions. It may appear as tiny pimples, or mosquito-like bites. It may also look similar to eczema or ringworm. It is important to see your healthcare provider for diagnosis and treatment.
Scabies may be more easily spread in nursing homes and other long-term care facilities because of the close contact of residents and staff. Scabies mites can also quicker among immunocompromised people, such as those with HIV/AIDS, or cancer.