The Australasian Society of Clinical Immunology and Allergy

Atopic eczema occurs in around 1 in 5 infants, but usually improves during the teenage years. Most patients either have or will develop other allergies with age.

Content Last updated 5 January 2001

Eczema is a common cause of itch in infants

Eczema (also known as atopic dermatitis) occurs in 1 in 5 infants, but usually improves during the teenage years. It usually results in dry, red, scaly and itchy skin. Sometimes weeping "sores" may develop as well, particularly if scratched, and these can sometimes get infected. In early childhood, the rash is often present over the face, limbs or trunk. As people get older, it more commonly affects the "creases" such as inside the elbows, behind the knees and in the neck. Like many medical conditions, it usually lasts for several years. Eczema can be treated but there is no "cure".

The tendency to eczema is inherited

People with eczema frequently have other family members with allergies such as asthma, hay fever or eczema. This suggests that inherited (genetic) factors may increase the tendency to react to a wide range of environmental irritants.

Children with eczema frequently develop other allergies

Eczema is often called atopic eczema or "allergic" eczema. This is because many either already have other allergies (like hay fever, asthma or food allergy), or will go on to develop them later. The great majority of patients with eczema are either allergic to dust mite already or become so with time. In some studies it has been reported that up to 5 % of infants with eczema and a family history of allergy will develop food allergy and up to 40 % develop asthma, hay fever or both.

Eczema usually improves with age

Infantile eczema usually starts between 4 to 6 months of age and the baby develops a red rash, which may weep. It appears on the cheeks and may spread to the forehead and the backs of arms and legs. In severe cases it may involve the whole body. Heavy scaling similar to cradle cap may occur. Eczema usually disappears between the ages of three and five years.

Childhood eczema may follow or may start for the first time between the ages of 2-4 years. The rash is found in the creases of the elbows, behind the knees, across the ankles and may involve the face, ears and neck as well. This form of eczema usually disappears by the age of ten, but may continue into adult life.

Adult eczema usually has large areas of very itchy reddened weeping skin with the elbow creases, wrists, neck, ankles and behind the knees being especially badly affected. The condition tends to improve in middle life and is unusual in the elderly.

Contact with allergen can worsen eczema

Contact with allergens can worsen eczema, and avoidance often brings about improvement. For example, close contact with animal dander can cause itching and sometimes hives, as can sitting and playing on the grass. Worsening of eczema in spring and summer may also be due to pollen sensitivity. Scratching dust mite allergen (contained in their droppings or "poo") into the skin can increase inflammation. Strict dust avoidance measures (see Practical Advice information bulletin in this series) often help.

Eczema and food allergy

Food allergy does not cause eczema, but can worsen it in some children. It only occasionally aggravates eczema in adults. The most common causes are cows milk, soy protein, egg, nuts, seeds, wheat and seafood although sometimes other foods are involved. Fortunately, most food allergies that aggravate eczema will disappear within the first few years of life.

The majority of children with food allergy will get intensely itchy with large hives within an hour or less of eating. Sometimes infants will have more subtle symptoms, such as irritability or a slightly worse rash after a feed. Occasionally, infanys will even react to small amounts of food present in their mother's breast milk. If the mother avoids the food in her diet, the baby's eczema may improve.

Identification of the offending food (or foods) with allergy tests (skin prick testing or RAST blood testing) can help to identify the culprit(s) in many cases. Since not all positive skin tests and positive RAST are clinically relevant, the test results are best assessed by an experienced allergy specialist.

The final answer is provided by a temporary "elimination diet" of the offending foods. If the skin improves, foods are introduced one at a time to see whether the eczema flares up. If there is no improvement in two weeks on the elimination diet, it means that food is unlikely to be a problem.

Less commonly, reactions will be delayed over several days. Allergy testing is less reliable in this situation. Taking young children off wheat and milk is not appropriate for the majority. Long-term unsupervised (and often unnecessary) dietary restriction can lead to malnutrition. Elimination and challenge with foods should be undertaken only under medical supervision.

Not all eczema is allergic

Constant exposure to irritants like water, soap, grease, food or chemicals can damage the protective barrier function of the skin. Once the protective barrier of the skin is lost, dermatitis frequently develops. Certain foods and drink may aggravate eczema even if the person is not food allergic. Common triggers include spicy foods, curries, alcohol (especially red wine), strawberries, tomatoes and the food colouring tartrazine.

What else makes eczema worse?

Eczema often has a mind of its own, coming and going without any clear reason. Known aggravating factors include:

• Scratching!
• Dry skin
• Heat
• Wool, nylon and acrylic fibres
• Sand pits
• Viral infections
• Skin infections with the bacteria Staph aureus
• Food allergy
• Food irritants e.g. citrus, tomatoes, Vegemite
• Hives / urticaria
• Climate changes
• Contact with allergen e.g. dust mite & pets
• Other irritants e.g. soap, chlorinated pool water
• Stress can make it worse but eczema is not a psychological condition.

Principles of Therapy

• Avoid irritants and known aggravates - always
• Maintain the protective barrier function of the skin - always
• Reduce inflammation of eczema with cortisone/steroid lotions - when needed

Avoid irritants

Eczema skin has a lower oil and water content than usual and is much easier to irritate than normal skin. Use cotton clothing in children and do not overdress or overheat. "Night gloves" and neatly clipped fingernails will reduce the damage from scratching by youngsters. Avoid woollen clothes, perfumes, soaps and chemicals.

Good skin care

Hot water washing with excessive use of soap removes skin moisture and worsens the itch. Bathing in warm or tepid water, using a soap substitute or bath oil and liberal application of moisturisers (eg. sorbolene) all help to return the skin from a dry, cracked state to an intact barrier that is more resistant to irritants.

Using cortisone creams wisely

These are applied to inflamed red and itchy areas. They are the only medications that will reduce the inflammation of eczema. They do not cure! The preparations used vary in strength. Your doctor will advise you as to the most suitable preparations for your problem. Shiny skin, thin skin, stretch marks or easy bruising are the major concerns with repeated use. The skin of the face and neck is more sensitive to the side effects of steroid preparations. Directions should be carefully followed to avoid side effects, and creams meant for the body should never be used on the face.

Other forms of therapy

• Cortisone tablets are only rarely used to treat eczema, and even then only for short periods.
• Antihistamines are generally of little use in reducing the itch of eczema. Older, drowsy antihistamines sometimes help people sleep through their itch.
• Antibiotics may be necessary when eczema becomes infected.
• Immune suppressants are sometimes needed when the inflammation of eczema is very hard to control. They need to be used carefully and under close medical supervision.
• Ultraviolet light ("PUVA") reduces inflammation
• Relaxation therapy may help when stress pays a role. Stress management courses sometimes help.
• Evening Primrose Oil is very popular to moisten the skin. Evidence of effectiveness is controversial.
• Specific medication is available for patients suffering from hereditary angioedema.

It is important to note that information contained in this bulletin is not intended to replace professional medical advice. Any questions regarding a medical diagnosis or treatment should be directed to a medical practitioner.

References

1. O'Byrne PM, Inman MD. The clinical expression of allergy in the lungs. Allergy Jan 1999; 54 (1): 7-14
2. Pauwels R. Influence of treatment of the nose and / or lungs. Clin Exp Allergy 1998; (28 S2): 37-40
3. Platts Mills T. Allergens and asthma. Allergy Proc 1990; 11(6) 269-701
4. 21st century Management of upper respiratory allergic diseases: A focus on allergy and asthma J Allergy Clin Immunol 1998; 101(2 Pt 2) S345-424
5. Gustafsson D. Development of allergies and asthma in infants and young children with atopic dermatitis - a prospective follow-up to 7 years of age. Allergy 2000; 55: 240-5.
6. Laan MP. Markers for early sensitisation and inflammation in relation to clinical manifestations of atopic disease up to 2 years of age in 1333 high-risk children. Clin Exp Allergy 2000; 30: 944-53.