According to the American Academy of Dermatology (AAD), scabies is caused by skin-to-skin transmission of the human itch mite. Scabies can also result from coming into physical contact with an infested object, such as bedding or a towel. Transmission of scabies cannot occur through animals, and the most common method of transmission between humans is sexual contact.
The AAD says that children, mothers, the elderly and sexually active young adults are the most susceptible demographics to scabies. A weakened or compromised immune system, such as that resulting from HIV/AIDS or leukemia, is another factor in increasing the likelihood and severity of infection. Those who have had organ transplants are also at an increased risk. In extreme cases of scabies, crusted lesions appear on the skin. Scabies becomes much more transmittable as a result of the crusted, flaked skin that can fall off and sustain the mites for up to a week without human contact.
The first symptoms of scabies are difficult to notice in some cases and may not become apparent until six weeks following infestation, according to the AAD. Symptoms include itching (particularly at night), a rash consisting of tiny bumps, scaly patches that resemble eczema, sores and thick crusts on the skin. Most cases of scabies can be successfully treated with specially prescribed topical cream that is applied directly to the skin.