What is Allergy?
Most people probably know what allergy is – you touch or eat something, or you take a medicine or get stung, and your body reacts in an abnormal, unpleasant and unhelpful way. In mild reactions there is an itchy rash or some swelling, but sometimes there are more severe reactions, including anaphylaxis.
In medicine, we recognize that the body has all kinds of ways of responding to these kinds of things, and we only call it allergy if the reaction is driven by the immune system.
If it’s not an Allergy, What is it?
Other kinds of reactions can happen that are not caused by the immune system, although they can look pretty similar. People often think they are allergic to something because it makes them feel sick or unwell, but there are other causes such as chemicals in foods, or lack of enzymes in the gut, or an abnormal gut lining, which are nothing to do with the immune system.
There are different names for these kinds of problems e.g. salicylate sensitivity, lactose intolerance etc. Coeliac disease is caused by an abnormal immune response to wheat, but this is a different kind of reaction than that seen in allergy.
Some people get rashes or swelling that can look allergic, but it is not because something they have come into contact with or eaten has triggered their immune system. Instead, their immune system has started to misbehave for some other reason, often an infection.
Explaining allergy to a child
This has to be tailored to the child’s age and stage of development. You will need to devise a strategy that seems most appropriate for your child. In general the child needs to know that their bodies can react when meeting a certain group of allergens, when they might encounter these and what the nature of this reaction is so that they can recognise the signs. This needs to be explained initially in simple terms and this message needs to be periodically reinforced and reiterated in an age appropriate manner.
In terms of food allergy, even very young children can be taught to tell people they have an allergy, to refuse food if they don’t know what it is, and to ask what a food contains before eating it. If this is something that has been a part of their lives from their early years, they may be quite accepting of this as they know no different.