Scabies

Published by Bupa's Health Information Team, April 2010.

This factsheet is for people who have scabies, or who would like more information about it.

Scabies is an intensely itchy skin condition that is caused by a tiny mite. It is highly contagious and spreads through close physical contact. With the right treatment, it can be cured quickly.

About scabies

Scabies is caused by a mite called Sarcoptes scabiei. The mites, which are less than half a millimetre long, burrow into the upper layers of your skin, where they live and lay their eggs. The combination of the mites, their eggs, saliva and faeces causes an allergic reaction, which results in a rash and intense itching.

In the UK, about one in 1,000 people go to see their GP about scabies every month, and the numbers are rising. It's most common in cities and during the UK's winter months.

Scabies can occur at any age, but it's most common among children.

Symptoms of scabies

Most people with scabies have a pimple-like rash, which is intensely itchy. The itching is often worse at night or when the skin is hot, for instance, after a bath or shower.

You can get scabies on your hands (particularly between the fingers), wrists, ankles and buttocks. If you are a man, you can get scabies on your penis and scrotum. If you are a woman, you can get it on the skin of your nipples. Children can get scabies on the palms of their hands and soles of their feet. In young babies, scabies may trigger widespread eczema (itchy and scaly skin), especially on the abdomen (tummy), chest and back, as well as the development of pinkish-brown nodules.

As well as itching and redness, you may have small nodules or bumps on your skin that may be filled with pus. You may be able to see small burrow marks near the site of the rash. These look like thin, scaly, zigzagging lines that are greyish-white or skin-coloured. The burrow marks can often be difficult to see as they are very short in length (less than 1cm) and may be obscured by the rash.

If you have never had scabies before, you may not develop any symptoms for up to six weeks after you have caught the scabies mite. However, if you have had scabies before, your symptoms may develop much sooner - usually after only a couple of days.

If you have any of these symptoms, see your GP.

Complications of scabies

Norwegian scabies

Some people develop a more severe form of scabies called crusted or Norwegian scabies. If you have this condition, thick crusts containing lots of scabies mites and eggs form on the surface of your skin. Norwegian scabies isn't as itchy as normal scabies - it may not itch at all - but it's very contagious. As well as being able to catch it through direct contact, you can also get Norwegian scabies from sharing bedding, towels and clothes with someone who has it.

Norwegian scabies is more likely to develop if you have a weakened immune system. This means you are more at risk of getting the condition if you are taking medicines that suppress your immune system, or have HIV infection or AIDS. You're also more likely to develop Norwegian scabies if you have a neurological condition, which affects your central nervous system, or are elderly.

Your GP may refer you to a dermatologist (a doctor who specialises in skin conditions) if you have Norwegian scabies.

Other skin conditions

A scabies rash can also trigger other skin conditions such as eczema (itchy and scaly skin) or psoriasis (scaly skin).

Psychological conditions

After having scabies, or other types of insect infestation, some people may believe they are still infested, imagining bites or itching when there is no mite present. This can be a very powerful illusion, and is known medically as delusions of parasitosis. If you still feel very itchy, even after treatment, talk to your GP for more advice.

Causes of scabies

Scabies is highly contagious and is spread easily by direct skin-to-skin contact. You can catch scabies from sexual partners who are infested. It can also be passed from one person to another by holding hands for a long time. It's unlikely, however, that you can catch scabies from a handshake or a hug. Mites can't live for very long away from their host, so it's rare to become infested if you share bedding or clothes with someone who has scabies. You should make sure you wash your linen as usual.

Scabies can leave you with feelings of guilt and shame, but it isn't necessarily a reflection of poor hygiene, just that you came into contact with the mite.

Diagnosis of scabies

Your GP will ask about your symptoms and examine you. He or she may also ask if you have come into contact with anyone else with scabies, or if anyone else in your family has had itchy rashes as well.

Scabies is sometimes difficult to diagnose because other skin conditions (particularly some forms of eczema) can cause similar itchy rashes. However, your GP may be able to tell if you have scabies if there are burrow marks in your skin.

Treatment of scabies

Scabies is treated with an insecticide cream or lotion, called a scabicide. You can buy scabicides at a pharmacy without a prescription from your GP. Always make sure you read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.

It's important that you apply the scabicide in the correct way.

• You will need to apply the scabicide all over your body, starting from your neck down. Your skin should be clean, cool and dry. Don't apply the scabicide after a hot bath as the heat will cause it to be more deeply absorbed, and to be effective it needs to stay on the surface of the skin.
• Make sure you cover every single bit of your body; especially your armpits, genitals, the webs between your fingers, and underneath your fingernails. If you are immunosuppressed or elderly, you will also need to apply the treatment to your face and scalp. As some parts on your body are difficult to reach, you may need some help to make sure you have covered everywhere.
• Depending on which particular scabicide you use, you will need to leave the treatment on for between eight and 24 hours - it is therefore a good idea to put it on overnight. If you wash your hands after you have put the scabicide on, remember to re-apply it wherever it has come off.
• Once the treatment time has passed, wash the scabicide off thoroughly with plain, cool water.
• Unless you have been given specific instructions by your GP, you will usually need to apply the treatment again after a week.

When you are treated for scabies, all your close contacts such as family members or people you live with will also need to be treated at the same time, even if they don't have any symptoms. This is to make sure that all of the mites are killed and that you are not re-infested.

After treatment, your skin will probably continue to feel itchy for two to three weeks, and may even feel worse. This is normal and doesn't mean that the treatment hasn't worked. Your GP may give you an anti-itch cream or antihistamine tablets to make you feel more comfortable.

Even if the treatment has worked, some people may develop itchy brown nodules, as wide as 2cm, on their genitalia or armpits. These usually disappear after about three months but can sometimes last up to a year.

Washing linen during treatment

If you have scabies, you will need to machine wash all your bed clothes and linen at a hot temperature (about 50°C or above) on the day you start your treatment. This is to make sure that all the scabies mites are killed. If you can't machine wash an item of clothing, keep it sealed in a plastic bag for 72 hours to keep any remaining mites contained until they die naturally. You don't need to fumigate any living areas to get rid of the mites.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.