Scabies
|
Scabies can affect anyone of any age. It causes a rash and itch. It can be passed on to others. Treatment with a cream or lotion will usually clear scabies, but you need to apply it properly. |
What causes scabies?
Scabies is caused by a mite (a tiny insect). The female mite tunnels into the skin and lays eggs. The eggs hatch into mites after a few days.
How do you get scabies?
You need close skin-to-skin contact with an infected person to catch scabies. The mites live in skin but die after a short time if they are away from the skin.
Most cases are probably caught from holding hands with an infected person. The hand is the most common site to be first affected. Sleeping in the same bed, and sexual contact are other common ways of passing on the mite.
Sometimes outbreaks of scabies occur in nurseries or residential homes where people are in close contact.
What are the symptoms of scabies?
- Itch is often severe. Itchy skin tends to be in one area at first (often the hands), and then spreads to other parts of the body. The itch tends to be worse at night and after a hot bath.
- A rash usually appears soon after the itch starts. It is typically a blotchy red rash that can appear anywhere on the body. It is often most obvious on the inside of the thighs, parts of the abdomen, and the ankles.
- Mite tunnels (burrows) may be seen on the skin as fine, dark, or silvery lines about 2-10 mm long. The most common areas where they occur are the loose skin between the fingers, the front of wrists and elbows, the groin, armpits, under breasts, scrotum, and penis.
- Scratching sometimes causes slight skin damage. In some cases the damaged skin becomes infected by bacteria - a 'secondary' skin infection. Skin infected with bacteria becomes red, inflamed, hot and tender.
The itch and rash of scabies are due to an allergy to the mites. These symptoms usually take 2-6 weeks to occur after you are infected (as the allergy develops). So you may not know that you are infected, and you may pass the mite on to others before you have any symptoms.
Some people believe that they are 'covered in mites'. This is usually not so. Commonly there are just a few mites on the skin. But, the allergy to mites can cause you to itch all over, and for a rash to appear in many parts of the body.
Who should be treated?
- The affected person AND...
- All household members and sleeping / sexual partners of the affected person - even if they have no symptoms. This is because it can take up to 6 weeks to develop symptoms after you become infected. Close contacts may be infected, but have no symptoms, and may pass on the mite.
Note: everyone who is treated should be treated at the same time.
What is the treatment for scabies?
The usual treatment is a either a cream containing permethrin or a lotion containing malathion. These kill the mite. You can buy them from pharmacies. You can also get them on prescription. They are easy to apply and normally work well if used properly. Re-apply the same treatment seven days after the first application. This helps to make sure that all the mites are killed.
Follow the instructions on the packet. The following is a general guide giving tips for success.
- You need to treat all the skin of your body (including the back, soles of the feet, between fingers and toes, under fingernails, scalp, neck, face, ears, and genitals).
- An adult needs at least 30 g of cream or 100 ml of lotion to cover the whole body. So, for two applications you will need at least 60 g of cream or 200 ml of lotion per adult.
- A small paintbrush is a good way of applying a lotion (but use cotton wool for sensitive areas such as the penis). A water based lotion is preferable as alcohol based lotions may sting.
- Apply cream or lotion to cool dry skin (not after a hot bath).
- The cream or lotion should be left on for the full recommended time. Depending on which one you use, this may be between 8 and 24 hours.
- Children should stay off school until the first application of treatment has been completed.
- If you wash your hands or any other part of your body during the treatment period, you should re-apply the cream or lotion to the washed areas.
- Clothes, towels, and bed linen should be machine washed (at 50 degree Celsius or above) after the first application of treatment. This is to prevent re-infestation and transmission to others. Items that cannot be washed can be kept in plastic bags for at least 72 hours to contain the mites until they die.
- Tell the pharmacist or doctor if treatment is for pregnant or breast feeding women, or babies under 6 months.
- Put mittens on babies to stop them licking the cream or lotion off their hands.
- Some people who develop a secondary skin infection may also need antibiotics.
Note: you will still be itchy for a while after successful treatment
It is normal to take up to 2-3 weeks for the itch to go completely after the mites have been killed by treatment. A soothing cream such as crotamiton may help until the itch eases. An antihistamine medicine such as chlorpheniramine may also be useful to help you sleep if itching is a problem at night (particularly for children). A pharmacist can advise about these.
See a doctor if the itch persists longer than 2-3 weeks after treatment. Sometimes the first treatment does not work, and a different one is then needed. However, the common reasons why treatment fails, or for scabies to recur, are:
- the cream or lotion is not put on correctly for the full time, or
- a close contact is not treated at the same time, and the infection is passed back and forth.
Symptoms with a recurring infection
If you have previously had scabies, had it treated and cleared, and then get it again, the symptoms may be slightly different. The itch and rash tend to develop straight away. (As mentioned above, the itch and rash normally take 2-6 weeks to develop when you have a first infection.) This is because you are already sensitised to the mite from the original infection. So, your body reacts with the itch and rash much sooner than after a first infection.
© EMIS and PIP 2004 Updated: January 2004 CHIQ Accredited PRODIGY Validated
Comprehensive patient resources are available at www.patient.co.uk