:: Allergy Clinic

:: Allergy testing

Before appreciating what allergy testing is and what it means, we must first consider the questions which are asked by many sufferers, their families and carers.

:: What is Allergy?

The term allergy is used to describe a response, within the body, to a substance, which is not necessarily harmful in itself, but results in an immune response and a reaction that causes symptoms and disease in a predisposed person, which in turn can cause inconvenience, or a great deal of misery.

Allergy is extremely widespread and affects approximately one in four of the population in the UK at some time in their life. Each year the numbers are increasing by 5% with as many as half of all sufferers being children.

:: What is the difference between Allergy, Intolerance, and Sensitivity?

Although the word “Allergy” is commonly used to describe any unpleasant reaction to a drug, food, insect sting, or chemical, this can be misleading. The word should only really be used to describe a reaction produced when the body meets a normally harmless substance, which has been “remembered” from a previous exposure and subsequently produces the “IgE” antibody.

“Sensitivity” is a reaction to a substance, which is an exaggeration of a normal side effect produced by that substance. For example, reliever inhalers used in asthma, if given at too high a dose in a particular individual may cause them to “shake”.

“Intolerance” happens when unpleasant symptoms occur after eating a substance, which your body cannot handle because the digestive system does not produce sufficient quantities of a particular enzyme/chemical, which is needed to break down the food and aid digestion, eg wheat intolerance.

The causes of symptoms need to be correctly diagnosed so that the management and treatment for either allergy, sensitivity or intolerance can be appropriately taken.

:: How do you know you have an allergy?

Often the history can help towards identifying allergens. Even if you know what is causing your allergic reaction, you may still need to have confirmation of the offending allergen. This is especially important if you have had a severe reaction and if there is any confusion as to whether your symptoms are caused by a true allergy (involving the production of IgE) or whether some other process is involved. Allergy testing can help clear any doubts.

As stated at the beginning (1 in 4) 25% of the population will at some time in their life see a doctor because of an allergy, as a consequence and frequency of these problems allergy testing is becoming increasingly sophisticated.