Atopic 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 early childhood, around three months of age, and tends to run in atopic families.
Possible causes include:
- Food allergy, which plays an important role in children under one year but not in adults
- Cow's milk, hen's eggs and peanuts are the foods most likely to exacerbate infantile eczema
- House dust mites tend to aggravate eczema in older children and adults
- Pet dander exposure, such as to cats, dogs and other furry animals, may play a role
- Certain bacteria may cause sudden, severe outbreaks of eczema
Contact dermatitis
This condition affects mainly adults. It occurs on skin contact with a chemical substance and takes 24 hours to develop.
There are two types of contact dermatitis:
- Allergic contact dermatitis - the skin becomes sensitised to something over a period of time and an allergic reaction occurs on re-exposure
- Irritant contact dermatitis - occurs when the skin comes in contact with something that strips away its natural oils and makes the skin red, dry, cracked and itchy
Irritant contact dermatitis is not an allergy.
An estimated one in 12 adults and one in five school-age children have eczema. According to the Health & 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
- Shampoos
- Disinfectants and bleaches
Eczema 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.
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, skin fungal and wart infections.
Up to half of all babies with widespread atopic eczema will later develop asthma and rhinitis as the eczema improves. This phenomenon is referred to as the 'allergic march'.
Diagnosing the cause of eczema
If you have contact dermatitis, you must try to identify the cause so you can avoid it. Patch testing with various chemicals can help in this.
If you have atopic eczema, you may be able to find out what you're allergic to by having special skin-prick tests for environmental and food allergens. Once an allergen has been identified, practical steps can be taken to avoid it.
Eczema treatments
Completely avoid the substance that triggers the eczematous rash and treat any existing rash with medium potency steroid ointments and moisturising 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 which one works best for you.
People with atopic eczema should bath regularly using liberal amounts of emollients (moisturising creams, ointments, lotions and bath oils) to soften and hydrate the skin. Ointments work much better than creams on dry eczematous skin, but are greasy.
Avoid perfumed moisturisers and those with added lanolin.
Outbreaks of eczema should be treated with adequate amounts of steroid ointments to reduce skin inflammation. These will only make the eczema better if used continuously for five to seven days.
Don't be afraid to use steroid ointments - they'll clear the eczema so moisturiser can continue to protect the skin. Moisturisers and creams alone won't settle active eczema.
You may be given antihistamine medication to make your skin less itchy. This should also help you to sleep better at night by reducing itching. In severe atopic eczema, you may be given a short course of oral steroid tablets to get the inflammation under control.
Antibiotics may occasionally be needed to treat impetigo and eczema flare-ups caused by staphylococcus and streptococcus bacteria.
'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. It 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.
Reducing intake of histamine-containing foods, such as tomato, berries, strong cheese, chocolate, Marmite and dark-meat fish, may reduce itching and redness.
Newer non-steroidal eczema creams, called tacrolimus and pimecrolimus, seem to be effective for clearing eczema on sensitive skin such as the face, and have no steroid side-effects.
There's mounting evidence that supplementing probiotic 'good bacteria' in a child's early diet will reduce the risks of developing eczema. Adding omega-3 essential oils to the diet may also be beneficial.
If you have atopic eczema you may find the following useful:
- Take lukewarm baths with emollients, but 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
