Eczema

What is eczema?

Eczema (also called atopic dermatitis or atopic eczema/dermatitis syndrome [AEDS]) is a disease caused by inflammation of the skin and the skin's inability to retain adequate moisture. The result is a dry and very troublesome rash and intense itching, which may occur on almost any part of the body.

In normal, healthy skin, which is pliable and elastic, a controlled amount of water is permitted to pass through the layers of the skin to ensure that the outermost areas remain properly hydrated. A number of factors may result in the impairment of the natural skin barrier function: genetics, allergens, washing chemicals, etc. As a result, the skin may become more susceptible to skin disease and more sensitive to the repeated use of water, detergents and other irritants. It will also lose its ability to retain moisture.

Eczema is largely a disease of childhood, but also affects adults.This is a condition that may commence a few weeks after birth, but usual onset is after the third month of life. In babies eczema may appear as a weepy rash on the face and inner creases or outer surfaces of arms and legs. In severe cases it may involve the whole body. Heavy scaling, similar to cradle cap, may occur.

In later childhood it becomes a dry, scaly, itchy rash in the inner creases of the elbows and knees. Some children may not outgrow eczema and the condition often continues into adulthood. In teenagers and young adults the creases of elbows and knees, the face (especially around the eyes), hands and feet are frequently affected.

About 50% of children with eczema develop allergic rhinitis, and between 20%-30% develop asthma. About 50% of children with eczema undergo complete, spontaneous resolution in time.

Itch/scratch cycle

One of the prominent symptoms is intense itching (pruritus). Scratching or rubbing the affected skin causes further release of irritating chemicals in and under the skin. These chemicals further irritate the skin and increase itchiness, which in turn increases scratching. Ensure therefore that fingernails are clean and cut short and that medication is sufficient to abolish this symptom. An increased dose or change of medication may be required.

Other rashes

Not all rashes in children are eczema and a number may mimic eczema, for example nappy rash, seborrhoeic dermatitis, contact dermatitis and psoriasis. Contact dermatitis is a rash that develops after contact with substances such as nickel, latex, dishwashing liquid and working with raw vegetables. These skin diseases may look similar to eczema, but are caused by different factors and are treated differently. It is important for a doctor to make the diagnosis of eczema and to rule out other causes.

What causes eczema?

Eczema typically runs a chronic course with exacerbations and remissions. A variety of 'trigger factors' may exacerbate eczema: irritants (e.g., soap, harsh chemicals, wool, heat and humidity, stress and anxiety), allergens (e.g. foods, house dust mites, moulds) and other foods through other mechanisms.

In children, a number of external factors may precipitate or aggravate the eczema, such as food allergens, house dust mites, etc, whereas in adults, the cause is often not found.

Diet-related causes

In babies, eczema may present soon after birth, usually as a result of allergens being transferred through the mother’s milk, and sometimes because of skin lotions containing allergens or chemicals. If the breast-feeding mother avoids the foods in question in her diet, the baby's eczema may improve.

Food is one of the most common aggravating factors in children with eczema, compared to adults where food is hardly ever related to their eczema.

Food allergy does not cause eczema, but may precipitate or exacerbate the condition. A baby with eczema is more likely to be allergic to food than other children. There is at least a 20 – 30% chance that food allergies may be triggers in a child with eczema.

The skin of the majority of children with food allergy will become intensely itchy with large hives, within an hour or less of eating. Sometimes babies will have more subtle symptoms, such as irritability or a slightly worse rash after a feed.

The foods responsible for 90% of these reactions are egg, peanuts, milk, soy, wheat, fish, nuts and shellfish, but any food may be the culprit. Food additives can also aggravate eczema in older children. Certain foods may aggravate eczema, even if the person is not food allergic. Common triggers include spicy foods, curries, alcohol (especially red wine), citrus fruit, strawberries, tomatoes, pineapple and the food colouring tartrazine.

Other aggravating factors in eczema

House dust mites are one of the most common aggravating factors of eczema. Appropriate measures should be taken to minimise the exposure to house dust mites.

Other common aggravators are smoking, pet hair, pollens and moulds. Stress and anxiety also play a big role in the aggravating of eczema, and in some children this may be due to the introduction of a food-elimination diet, so caution and balance is required before excluding foods from a diet!

Household items which may aggravate eczema include enzyme-enriched washing powders, fabric softeners, dishwashing liquid, bleach, soaps containing perfumes or alcohol, harsh chemicals and perfumes.Swimming pool chlorine may also irritate and dry out the skin. Local household skin irritants include wool, mohair, nylon and feathers. Remember that parents who work with chemicals or foods as an occupation or hobby can indirectly cause these substances to come into contact with their children, usually via their clothes.

Environmental factors that affect eczema are hot, humid and cold, dry weather, as well as excessive sweating. Do not overdress your child.

Treatment

The first step is to identify those factors causing or worsening the condition and then to avoid these factors. The second step is to reduce or stop itching. The third step is to keep the skin moist, and the fourth step is to manage the affected skin. A doctor with a special interest in the condition should be consulted.

Where stress might be a precipitating factor, various methods of stress management can be implemented – discuss this with your doctor.

Emollients

The most important treatment for the eczema is to moisturise the skin and to relieve the itch.

Moisturising creams and ointments are the mainstay of eczema treatment. They are completely safe and should be applied liberally at least twice daily to hydrate and protect the skin. Some people may find that certain of these preparations irritate their skin. If this occurs, another product should be tried. This is in true even for aqueous cream. Different emollients include Emulsifying ointment (HEB), aqueous cream (UEA), Cetomacrogol, Ultrabase and Oilatum cream. Sometimes coal-tar is applied to treat thickened skin.

Emollients are safe when the following guidelines are adhered to:

• Use frequently, especially when the skin feels dry and itchy
• Apply after a bath, when water has penetrated and hydrated the skin (see “bathing” below)
• Apply with clean hands. It is very easy for children with eczema to develop infected skin
• Gently apply a thin, even layer. Do not rub the skin too hard, as this can stimulate itching
• For thick preparations, use the dot method. Apply by dabbing small amounts (“dots”) where required, and rub in gently
• Each child with eczema should have a separate supply of emollient, to avoid cross-infection
• Your health practitioner may suggest either a “thin” or “viscous” product, depending on the condition of the eczema

Cortisone creams

These produce rapid relief and are used in higher strengths for short periods to settle eczema flare-ups. Following improvement, a long term steroid may still be required to control the affected skin. There are various strengths and your doctor will select the appropriate one. Steroid cream should be applied frequently and regularly and is usually applied after bath time, when the skin is hydrated and moisturised. Generally speaking, once the eczema is controlled, milder, diluted steroid creams may then be used. If they are used for longer periods they may be diluted in an emollient. There has been a fear that long-term use may lead to thinning of the skin. But the newer preparations are much safer. Directions should be carefully followed to avoid side effects, and creams meant for the body should never be used on the face. Cortisonetablets or injections are not often used in eczema, but there are particular situations where they may be used for a short term to bring the eczema under control. Uncommonly, some individuals become allergic to the skin treatment. Discuss this with your doctor. New treatments that are effective in some individuals may also result in less of the steroids being required.

Antibiotics

Eczema sufferers are more prone to skin infections (bacterial, fungal and viral, including the common wart). Oral antibiotics are usually prescribed to treat infected eczema, which may present as sudden development of crusting, oozing and redness of the skin.

Antihistamines

Itching is the most common but often least tolerated symptom of eczema. A substance called histamine, released from the damaged skin cells, causes the itch. Stimuli cause the release of histamine from cells. Antihistamines block the effect of histamine release and thereby stop or reduce the itch. Itching results in scratching, which releases further chemicals, resulting in a vicious cycle. It is important to get the itching under control and some children may require a larger dose than the normal prescribed dose, or even the use of a second medication. Note that it is vitally important to get the itching and scratching under control. Therefore, if the itching persists, discuss this with your doctor.The older sedating type antihistamine tablets or syrups such as Aterax are very effective and will reduce itching, and should especially be used at night, as they may help with sleep. Antihistamine creams may sensitise the skin and should be avoided.

Other therapies

Evening primrose oil (or gamma linolenic acid) has been tried and may work in some individuals, but research has not shown it to be a very successful treatment. Extracts of Chinese herbal tea are being evaluated.

Other recommendations

The more severe the eczema, the more stringently the following recommendations should be followed:

Bathing
Sit in a lukewarm bath for 20 minutes at least once a day in order to hydrate the skin. Use 100% cotton soft towels and never rub, but pat the skin dry. If non-perfumed soaps such as Pears, Dove or Neutragena irritate the skin then the use of aqueous cream, Aquabar or Cetaphil lotion is recommended.

Moisturising emollients should be applied to the skin within three minutes of patting the skin dry. You may find it helpful to use a kitchen timer to get used to a period of 3 minutes.

If using a new cream, ointment or soap, try some on a small patch of skin before applying it to the entire body to be sure it will not cause a reaction. Avoid the eyes. Consult your doctor about whether a particular product may be suitable for your skin or not.

Washing of clothes

Non-biological washing powders such as Sunlight and Skip should be used instead of enzyme enriched Punch, Biotex, Surf or Omo.

Sleeping
As much skin as possible should be covered with non-allergenic lightweight cotton clothing, taking care not to overdress or overheat the person. Cotton night gloves, as well as neatly clipped finger nails will reduce scratching. Sometimes elbow splints need to be applied to stop intractable scratching at night. If your child’s sleep is being affected by itching, then this clearly indicates that the itch is not adequately controlled.

Cotton underwear, clothing and bed linen are recommended. Wash all new clothes and bed sheets before using them to remove the chemicals introduced in the manufacturing process. Wash all bedding at temperatures above 55 degrees Celsius to eradicate mites and remove their faeces.

Your career and eczema

Young adults should decide on a career that is less likely to expose them to irritant chemicals and should probably avoid nursing, hairdressing, catering, motor mechanics or the building industry. Protective gloves with cotton linings will help prevent the irritant contact dermatitis that is so very common in eczema sufferers. Theyshould also ideally avoid stressful occupations (e.g. police work, nursing, etc). Some individuals are allergic to latex, so choose gloves carefully.

Can eczema be outgrown?

Eczema usually becomes less severe in the teens, and may be completely "outgrown" around puberty. The majority of people will remain symptom-free, apart from eczema on the hands due to contact with irritants such as detergents and oils. However, there may be a relapse in some patients around the age of 20. The reason for this is unclear. If eczema continues into the third, fourth and fifth decade, it is commonly "outgrown" at menopause in females. It is rare for it to continue into old age, but when it does it is often severe and widespread.

Dr H Steinman