There are several types of eczema, which affect children and adults, and have different causes. The two most common forms are atopic dermatitis and contact dermatitis.
This condition (also called atopic eczema or infantile eczema) affects people with dry and rough skin ('keratosis pilaris') and may be caused by a variety of allergens. It often starts in childhood and tends to run in families.
Possible causes include:
- Food allergy, which plays an important role in small children but not in adults
- Cow's milk and hen's eggs are the foods most likely to exacerbate infantile eczema
- House dust mites, which tends to affect older children and adults
- Pets, such as cats and dogs
- Certain bacteria, which may cause sudden, severe outbreaks of eczema
This condition usually only affects adults. It happens when the skin reacts to contact with a chemical substance.
There are two types of contact dermatitis:
- Allergic contact dermatitis, which occurs when the skin becomes sensitive to something over a period of time and develops an allergic reaction
- Irritant contact dermatitis, which occurs when the skin comes into contact with something that strips away the skin's natural oils and makes the skin red, dry, cracked and itchy
An estimated one in 12 adults and one in five school-age children have eczema. According to the Health and Safety Executive, occupational dermatitis (irritant contact dermatitis caused by sensitivity to substances at work) accounts for up to a third of all working days lost by British industry.
The most common causes of allergic contact dermatitis are:
- Nickel in jewellery and on clothing fasteners and studs
- Rubber and building materials such as cement, solvents and glues
- Ingredients found in cosmetics, hair dyes and perfumes
The most common causes of irritant contact dermatitis include:
- Soaps, detergents and fabric conditioners
- Disinfectants and bleaches
What are the symptoms?
In mild cases, eczema is nothing more than a slightly irritating patch of sore skin, but in severe cases extensive areas of skin may become inflamed and unbearably itchy. It's hardly surprising some people with these symptoms develop problems such as depression with low self-esteem, and have difficulty coping at school or work.
People with eczema are also more prone to herpes and wart infections.
Up to half of all babies with widespread atopic eczema will later develop asthma as the eczema improves
Unfortunately, up to half of all babies with widespread atopic eczema will later develop asthma as the eczema improves. This phenomenon is referred to as the allergic march.
How do you find the cause?
If you have contact dermatitis, you must try to identify the cause and avoid it. Patch tests are sometimes used to help identify the cause.
If you have atopic eczema, you may be able to find out what you're allergic to by having special tests for respiratory and food allergens. Once an allergen is identified, practical steps can be taken to avoid it.
What's the treatment?
Completely avoid the substance that triggers the eczematous rash and treat any existing rash with low-dose steroid ointments and emollients.
Atopic eczema is usually a little more difficult to treat and you may need to try a number of different treatments, or a combination of treatments, before finding out which one is best for you. People with atopic eczema should regularly use liberal amounts of emollients (moisturising creams, ointments, lotions and bath oils) to soften and hydrate their skin.
Outbreaks of eczema are usually treated with steroid creams that reduce skin inflammation. These nearly always make the eczema better but cannot get eliminate it completely.
You may be given antihistamines to make your skin less itchy. These should also help you to sleep better at night by reducing itch. In severe atopic eczema, you may be given a short course of oral steroid tablets.
Antibiotics may occasionally be needed to treat impetigo and eczema flare-ups caused by staphylococcus bacteria.
'Wet wrapping' is sometimes used overnight, particularly on children
'Wet wrapping' is sometimes used overnight, particularly on children, if emollients and steroid creams alone are not effective. The treatment involves applying wet tubular bandages over emollients and steroid creams to aid their absorption. This treatment also helps to relieve itching and prevent scratching. Evening primrose oil (or gamolenic acid) has been used to treat atopic eczema, but with disappointing results.
Some results from trials using Chinese herbal medicine to treat eczema have been encouraging, but it's important to remember that just because a treatment is 'herbal' or 'natural' doesn't mean it's safe for everyone.
Newer immuno-modulatory eczema creams called tacrolimus and pimecrolimus seem very effective for clearing eczema on sensitive skin such as the face and have no steroid side-effects.
If you have atopic eczema you may find the following useful:
- Take lukewarm baths with emollients and don't stay in the water too long
- Pat the skin dry with a towel - never rub eczematous skin dry
- Avoid soap, detergents and shampoo - use aqueous cream instead of soap
- Wear cotton fabrics next to your skin - avoid wool and polyester
- Wear loose rather than tight-fitting clothes
- Clip your fingernails and don't scratch or rub your skin
- Avoid sports that make you sweat a lot
- Try to stay calm and relaxed because stress can make eczema worse
For more information on treating and controlling eczema, contact the National Eczema Society.