Scabies is a very itchy rash caused by a parasitic mite that burrows in the skin surface. It can spread rapidly in crowded conditions because it is usually contracted from direct skin-to-skin contact with another person infected with scabies. Institutions such as prisons, nursing homes, child care centers or dormitories are common sites of scabies outbreaks. Often, if one member of a family is infected, the whole family becomes infected. It can also be spread by shared clothing or bedding, though this is less common.
The most common presenting symptom of a scabies infection is intense itching of the skin which is usually worse at night. A rash also usually appears with tiny sores or blisters that can become worse with scratching. Symptoms typically do not show up for 2 to 6 weeks, especially with a first infection. During this time, however, the infected person can still spread scabies to others which is why infection is so rapid and common.
In adults and adolescents, the infection is more commonly seen on the hands, wrists, abdomen and genitals. With young children, it is typically on the head, neck, shoulders, palms and soles of the feet. Infants may have a more widespread infection, with pimple-like outbreaks on their torso. Elderly people or those with compromised immune systems may also develop a severe form of scabies called crusted scabies or Norwegian scabies, characterized by thick crusts over the skin that contain large numbers of mites, sometimes in the millions.
A health care provider can diagnose scabies with a physical examination and a skin biopsy may be required to confirm diagnosis. Some options to ease the symptoms of scabies include prescription treatments, washing all underwear, bed linens, sleepwear and towels in hot water followed by hot drying, and vacuuming all carpets and upholstered furniture. This should also be done for all household members and sexual contacts. To treat the rash and itching, soak in a cool bath and then apply calamine lotion to the affected areas. An oral antihistamine or short course of topical steroid cream may be used.
There are no over-the-counter medications to eliminate scabies. Scabicide lotions or creams, which kill the mites and sometimes also the eggs, are available only with a doctor’s prescription. The lotion or cream is applied all over the body, from the neck to the feet, and left on for a recommended period of time. For hard to treat cases, an oral pill called Ivermectin may also be prescribed. The use of insecticide sprays or fumigators in the house or on the body or clothing is not recommended.