Definition

Scabies is a common contagious parasitic skin infection, accompanied by intense pruritus. Scabies in humans is caused when the skin is attacked by the human mite, Sarcoptes scabiei var. Hominis. The tiny mites that cause scabies infect the top layer of the epidermis, burrow into the skin, mate and lay eggs. The most common symptoms of scabies include intense itching (especially during the night) and skin rash.

Scabies mite is usually spread through direct, extended contact with the skin of a person who has scabies.

Scabies is a common condition found worldwide; it affects people of all races and social classes. Scabies can spread easily under crowded conditions where close body contact is common. Child care facilities also are a common site of scabies infestations. Outbreaks of scabies are common in nursing homes and prisons.

Scabies: Signs and Symptoms

After the mite burrows into the skin, it takes time to develop signs and symptoms of the infection.

When a person is infected for the first time by scabies, the body needs time to develop a reaction to the mite. It can take 2 to 6 weeks for the cutaneous lesions and symptoms to develop. If a person has had scabies in the past, the itching usually begins earlier, within 1 to 4 days, in case of a new infection.

Signs and symptoms of scabies include:

  • Itching, mainly at night: Itching is the most common symptom and it can be so intense that it keeps a person awake all night.
  • Rash: Many people get rash. This rash causes little bumps that often form a line. The bumps can look like hives, tiny bites, knots under the skin, or pimples. Some people develop scaly patches that look like eczema.
  • Sores: Scratching the skin and the itchy rash can cause sores, which may lead to an infection.
  • Thick crusts on the skin: Crusts form when a person develops a severe type of scabies called Norwegian scabies. In this type of scabies, the number of mites is great. It is a very contagious form of the disease, and it usually affects people with compromised immune system due to other medical conditions or due to the use of immunosuppressing drugs.

Scabies can develop anywhere on the skin. The mites, however, prefer to burrow in certain parts of the body. The most common places to have itching and a rash are:

  • Hands: The areas between the fingers, around the nails and the elbows are common places where mites are found.
  • Skin usually covered with clothes or jewellery: such as the buttocks, waist, penis, and the skin around the nipples are places preferred by mites. They also prefer the skin covered by a bracelet, watch or ring.

Treatments and Medication

Scabies treatment involves eliminating the infestation with medications. Several creams and lotions are available with a doctor’s prescription. Usually the medication is applied to your whole body, from the neck down to your toes, and left on for at least eight hours, while treatment may have to be repeated if new symptoms or rashes appear.

Because scabies spreads so easily, your doctor will likely recommend treatment for all household members and other close contacts, even if they show no signs of scabies infestation.