Scabies is an itchy condition of the skin caused by a tiny mite (Sarcoptes scabiei).

The mite burrows into the skin, especially around the hands, feet, and male genitalia. It does not usually affect the neck and head, although it may in infants.

The itching is due to an allergic reaction to the tiny mites, and is associated with a rash of red, raised spots. The itch is worse at night, and may often affect more than one family member.

Scabies is caused by a mite (Sarcoptes scabiei) which burrows under the skin, but the rash and itch are much more widespread than the location of the mites.

The mite may be passed easily by close contact and commonly starts at the wrist, presumably having been picked up through holding hands.

Diagnosis is often made clearer because more than one family member has an itchy rash. Sometimes burrows can be seen, especially near to the wrists. The doctor may sometimes manage to remove a mite from a burrow in order to look at it under magnification.

The diagnosis can be made difficult because the rash can look like other itchy conditions eg eczema.

There are three main types of treatment in use for scabies. All are applied to the whole body except the head and neck, and the whole family should be treated at the same time.

• The treatment of choice at the moment is Permethrin, in view of its relative safety, ease of application, and as it tends not to irritate the skin. This should be left on for at least eight hours. This may be used for the head and necks of children less than two years old.

• Benzyl benzoate emulsion. This is washed off after twenty four hours, and repeated two or three times. In infants or young children it is wise to dilute in two or three times as much water, as this helps reduce skin irritation.

• Malathion. This is washed off after twenty four hours.

The treatment kills the mites, but their bodies are still in the skin and as it is this that we are allergic to, the itch persists until our own natural defence systems break down and get rid of what is left of the mites. This process takes about two weeks and therefore the itch continues for about two weeks after the treatment.

Do not be disheartened, this is to be expected and does not mean that the treatment has failed. In the mean time you may find that an antihistamine tablet or medicine (either prescribed or bought over the counter) will reduce itching.