Allergic Eczema

Eczema is an inflammation of the skin that usually causes intense itching. The terms dermatitis, ‘skin inflammation’ and eczema are often used interchangeably. Atopic eczema is the allergic type of eczema. It often affects people who are atopic, which is a tendency to allergy, who may also have other allergic diseases, such as asthma. Eczema is a fairly common condition, affecting up to 15% of school-age children, and between 2-10% of adults.

Are there different types of eczema?

Besides atopic eczema, which is an allergic disease, there are various other forms of eczema. These include:

Asteatotic eczema. Seen mainly on the limbs of elderly patients, this form of eczema results from loss of natural lubrication of the epidermis and is characterised by large scales having a ‘crazy paving’ appearance.

Nummular or discoid eczema. The word 'nummus' is Latin for coin and describes the coin-shaped patches of inflammation occurring on the legs and trunk in nummular eczema. These are characterised by mild edema (swelling) and redness but are not always itchy.

Contact dermatitis. There are two forms of contact dermatitis. Allergic contact dermatitis is caused by direct exposure of the skin to a true allergen, while irritant contact dermatitis is caused by exposure to an irritant. The mechanisms of skin inflammation are different, but in both cases, the affected area of skin will become reddish brown on exposure and soon becomes painful and itchy, perhaps with blistering. Contact dermatitis often occurs among women doing a lot of domestic workers, who are exposed to soap, detergent, and water.

Seborrhoeic eczema. This form of dermatitis is characterised by yellowish scales – rather than a red itchy rash – which are found mainly on the scalp, face and nappy area in infants, and on the face, scalp, and chest in adults.

Dishydrotic eczema (pompholyx). Pompholyx (the word means ‘bubble’) is a characteristic pattern of intensely itchy vesicles on the skin of the hands, and maybe the soles of the feet. Sometimes the sides of the finger are involved, with the lesions being a little like grains of sago – often easier to feel than see. This form of eczema is often stress-related.

Stasis or varicose eczema. Another form of eczema common among older people, stasis eczema is most often seen in association with poor circulation in the lower limbs and varicose veins. It may also co-exist with leg ulceration.

Paget’s disease of the nipple. If eczema of the nipple area occurs in women, Paget’s disease associated with cancer of the breast ducts may be the underlying cause. A biopsy is essential in such cases.

The typical symptom of eczema is a ‘weeping’ itchy rash and redness of the skin. Other symptoms to note are:

• A rash can occur on any part of the body but is most commonly seen on the face, hands, elbows, wrists, buttocks, knees, and in folds of the skin
• A scaly appearance to the skin which is caused by scratching damage
• Dry, maybe thickened, skin but permanent scarring is rare
• The release of skin pigment granules may give the skin a dirty, unwashed, appearance

The initial symptom of atopic eczema is often a rash on the face, scalp or trunk, appearing when a child is no more than two or three months old. The rash might disappear, or it may spread to the body and limbs. Often it will settle in the creases of the elbows, wrists, buttocks, knees or ankles. Nearly every child with eczema has an affected patch in the crease beneath the earlobe while, conversely, some areas such as the nose, are rarely affected. The severity of atopic eczema varies widely at all ages. It may be no more than mild irritation, or it may be severely distressing and disabling.

Eczema usually clears in most children before they turn three years old. However, roughly 30% of children continue to suffer with eczema after they reach age three. The condition then takes on a different distribution as they get older and tends to be found more on the surface of the body, rather than the creases.

A baby has about a one in two chance of developing eczema if he or she already has a sibling with the condition. This is around five times the risk of a child born into a family with no history of eczema. It is not eczema itself that is inherited, but the predisposition to develop an allergic response to certain substances, otherwise known as atopy. Some people with atopy never develop eczema or any other atopic condition. The inheritance of atopy is dependent on inheriting a combination of several different genes. The genetic factor in eczema also interacts with environmental factors, so the pattern of inheritance is complex. If you or your partners have eczema, the risk of your child developing it is around one in four. You or your partner may not have eczema but it is not uncommon to see your child develop eczema.

Atopy is a tendency to develop an allergic response to certain substances commonly present in the environment, such as dietary components, house dust mite, moulds etc. Atopic eczema is one of a group of allergic diseases which also include asthma, urticaria, and hay fever. If you or your child has eczema, it is more than likely that one or more of these atopic conditions are present in your family history.

Atopic allergy, including atopic eczema, involves an over-reaction by the immune system to a normally harmless substance. In this response, an antibody molecule known as Immunoglobulin E is produced. This attaches to immune system cells known as mast cells. The mast cells produce many chemicals that trigger an inflammatory process which, in the case of eczema, means redness, vesicle formation, hotness, and a rash. Research into the causes of eczema is ongoing, because it may be that the immune response in eczema differs in some ways from that in other atopic diseases.

It is important, in eczema, to distinguish between allergens, which produce IgE, and irritants which cause a more general inflammatory response. The key allergens in eczema are:

• Foods: The most common food allergens are eggs and milk, especially among infants. In adults, acidic or salty foods are often the main culprits.
• Pollen: Wind-pollinated plants such as grass, followed by trees including alder, birch, hazel, oak, and beech are the main problem.
• House dust mites
• Pet Dander
• Mould: If you find eczema is at its peak in autumn, suspect moulds on fallen leaves, which also contain potential antigens.

Anyone diagnosed with eczema will probably have to be wary of a range of irritant substances for the rest of their lives. Irritants include:

• Soap
• Water
• Detergents
• Wool
• Nylon

Patch testing can reveal the nature of the allergen in contact dermatitis. Common allergens include:

• Nickel in jewellery
• Chromate in leather
• Lanolin and preservatives in creams and cosmetics
• Preservatives in rubber gloves

The doctor should take a medical history, including:

• How long the condition has been present
• What the symptoms are
• Family history
• Occupational history

The next step is a detailed examination of the whole of the skin surface, not just the hands, face or wherever the eczema is most troublesome, and in a good light. The doctor will check the distribution and nature of the lesions. If there is any suspicion that the skin is infected – a fairly common complication of eczema – then swabs may be taken for microbiological analysis. And if there is the slightest suggestion of skin cancer, then a biopsy will be taken and examined for malignant cells.

Can eczema be confused with other diseases?

Eczema can easily be confused with other diseases. The lesions are not dissimilar to those caused by ringworm (tinea), a fungal infection. The two conditions can be distinguished by the laboratory culture of a swab from the lesion, which will reveal any infection present. Psoriasis is another inflammatory condition which may be confused with eczema.

Many factors in the home environment may trigger a flare-up of eczemas, such as allergens and hot, dry air. Try these tips to avoid an eczema attack:

• Consider a humidifier to reduce dryness
• Use a moisturising fragrance-free oatmeal cream
• Turn down your central heating
• Minimise exposure to house dust mite and other allergens with regular use of allergy-friendly cleaning products and thorough vacuuming
• Consider investing in an air purifier

With eczema, it is really important to keep the skin moisturised. Regular baths in warm water are an excellent way of moisturising skin and keeping it clean. It also helps any treatments you may be used to penetrate the skin better. But instead of soap, you should use specially-formulated bath oil. Regular moisturising of the skin with creams and lotions will also be an important part of your routine. When using creams make sure they are free of formaldehyde, fragrances, dyes, and parabens.

What medical treatments are there for eczema?

There is no cure for eczema, however, there is a wide range of treatments that will keep the condition under control. The mainstay of treatment is a good quality ointment, cream or lotion, like the E45 range, that suits your skin. This at least prevents the skin from damage during a bout of scratching.

In many cases, creams containing steroids such as hydrocortisone are used to damp down the inflammation. Oral steroids are generally reserved for severe ‘flare ups’ because of the danger of side effects.

Some people with eczema have a fear of using steroid creams to treat their condition. In fact, steroid creams when used correctly are safe and play an important role in damping down the inflammatory process underlying a flare-up of eczema. It’s important to use the minimum strength of steroid cream to keep your eczema under control and to use it for limited periods only. Topical steroids, if misused or used for long periods, are associated with a number of side effects, the most significant of which is thinning of the skin. There are also non-steroidal treatments for eczema, either in a cream or as an ointment. Both are immunosuppressant drugs which work by damping down the immune system to tackle the underlying inflammation in eczema.