What is Eczema?

This condition is also called atopic dermatitis. This is largely a disease of children but also affects adults. It usually starts at 2-4 months of age. It is a hereditary skin disorder most often associated with asthma and allergic rhinitis. Eczema results in thickening, excoriation and often infection of the skin. In young children the face and neck are mainly affected. The rash is red, very itchy and weepy on the cheeks. It then spreads to the flexural areas of the arms and legs. The disease usually undergoes resolution and exacerbation. About 50% of the children with eczema develop allergic rhinitis and between 20%-30% develop asthma. About 50% of children with eczema undergo complete spontaneous resolution in time.

The exact causes of eczema are not known but are probably multifactorial. Patients with eczema may have an allergic tendency which they inherited from their parents. Ingestion of foods such as cow's milk, eggs, wheat, soya protein, peanuts, fish and citrus cause or worsen the condition. Allergy to house-dust mites can also cause or worsen eczema. Many other factors such as changes in skin proteins, an abnormal immune response as well as an abnormal neural response involving the autonomic nervous system are thought to play a role in eczema.

Treatment involves many steps, but the first step is to identify those factors causing or worsening the condition and then to avoid these factors. This may involve avoiding cow's milk, eggs, wheat, soya protein, fish and citrus fruit, but only if those foods are definitely the cause. Allergy blood testing is not the decider in avoiding these foods. Children must usually be tested by means of food challenge testing.

The most important treatment for the eczema is to moisturise the skin and to relieve the itch. Moisturisers must be used frequently and regularly.

Steroid cream is used for ‘flare-ups’.

Written by Prof Robin Green

Children’s Chest and Allergy Clinic

Steve Biko Academic Hospital