Just because you have an unpleasant reaction to something you eat – does not necessarily mean you have an allergy. However, if you are experiencing extreme physical pain or illness reassuringly, and this is adversely affecting your day-to-day life, the chances are you may have a dietary intolerance. Food allergies involve a process in your immune system where your body produces something called ‘antibodies’. These antibodies are known as ‘immunoglobulin’ (IgE) and triggers a response to foods that they identify as harmful. This releases a cellular response – this is the reaction that would be identified as the allergy.

How to identify it

Diagnosing a food intolerance can be a little tricky, this is because the symptoms and side effects can vary significantly from person to person. This means that your GP will perform a variety of tests to attempt to pinpoint what the cause may be. This commonly involves the exclusion of certain foods from your diet until the culprit is identified but can also involve having a blood test. Your GP may also recommend you keep a food diary, documenting the various things you have eaten and what reactions you have.

Allergy testing

You may be advised instead to have an allergy test. This can involve a skin or blood test and involves a miniscule drop of liquid food extract being placed on the skin – one from each of the food groups that needs to be tested. The skin will then be very lightly pricked. A raised bump with redness around it may appear – being an indication that you are allergic to this particular type of food. A skin or blood test can highlight an intolerance but in some cases you may only become aware of an allergy when you have had a previous adverse reaction to food.

Blood testing, on the other hand, is something that is a little more common if it is believed that you may be celiac or be lactose intolerant. The celiac blood test will pick up the autoantibodies in a sample of blood. The lactose intolerance test, however, involves you drinking a fluid containing lactose and then following it up with a blood test up to two hours later. If the blood glucose levels don’t rise – this most likely means that your body is not digesting lactose and you are intolerant.


There’s no getting past the fact that identifying an intolerance is tricky. Although it can be a case of trial and error – following your GP’s advice and documenting your diet as well as pursuing an allergy test if needs be, is a surefire way to ensure you find the cause of the problem.

If you believe you require a blood test or any other form of allergy testing, Duality Healthcare are here to support your needs. Our dedicated and reliable team put you first and ensure that you experience smoothly and efficiently. If you are based around Newry and Dungannon and require an appointment, please don’t hesitate to get in touch with us today.