Everyone is familiar with skin rashes, which can be due to a variety of causes. Rashes which are caused by food allergy are distinctive and may be diagnosed as either `atopic eczema' or urticaria'.
Atopic eczema
This skin disorder affects about 5% of all young children and is often caused by food allergy. It may show up as a dry and scaly or rather `weepy', itchy rash on the child's cheeks, neck, inside the elbows and behind the knees. The rash is usually followed by an outbreak of asthma or hay fever. Doctors treat atopic eczema by first putting the child on a diet which excludes known allergens (such as wheat and dairy products), which often solves the problem. Obviously, if the eczema flares up again when these foods are reintroduced, this confirms the relationship. Special tests can also be done to identify problem foods. Egg white and wheat are two of the most common ones and cow's milk and soya often cause trouble as well.
Urticaria
You can identify urticaria - also known as 'hives' or 'nettle rash' by raised red (and itchy) welts which usually start on the face and body and spread to arms and legs. Shellfish, nuts, tomatoes, milk and eggs
are typical culprits. Other possible causes are food additives - such as tartrazine, benzoates, quinoline yellow, BHA (butylhydroxyanisol) and BHT (butylhydroxytoluene) - and drugs such as antibiotics and aspirin. Urticaria may occur in adults or children and is not more common in any particular age group. It often occurs in people who have never had any other prior allergic condition in their lives.