“How can I find out if I have food allergies?”
If you suspect that you have any allergies, you should first contact your doctor, who may offer a blood test to identify the cause of your allergy. Most allergy tests are done in hospital outpatient clinics. Not every hospital has an allergy department, so you might have to find a local allergy clinic recommended by your doctor. At the clinic, the type of test you will receive will depend on your symptoms.
A skin prick test is usually the first test to be done when looking for an allergen. It’s quick, painless and safe, and you get the results within about 20 minutes. Your skin is pricked with a tiny amount of the suspected allergen to see if there’s a reaction. If there is, the skin around the prick will very quickly become itchy and a red weal (swollen mark) will appear.
The blood test used to test for allergens is called a specific IgE test (formally known as the RAST test). It is used to measure the number of IgE antibodies in your blood that have been produced by your immune system in response to a suspected allergen.
The patch test is used to see if a skin reaction, for example eczema, is caused by contact with a specific chemical or substance. A small amount of the suspect substance or chemical, such as nickel, is added to special metal discs, which are taped to your skin for 48 hours and monitored for a reaction. This test is usually carried out at a dermatology department in a hospital.
A food challenge, also called an oral challenge, is the most accurate way to diagnose a food allergy. During the test, you’re given the food to which you think you are allergic in gradually increasing amounts to see how you react. Only one food can be tested at each appointment.
*Beware of some commercial allergy testing kits, such as hair analysis tests, kinesiology tests and VEGA tests, which are not recommended by doctors because there is little scientific evidence to support them.
Genuine food allergy is rare. About 2% of the population and 8% of children under the age of three are affected.
A food allergy is a rapid and potentially serious response to a food by your immune system. It can trigger classic allergy symptoms such as a rash, wheezing and itching, and in the case of an anaphylaxis attack, it can cause death.
The most common food allergies among adults are to fish, shellfish and nuts, including peanuts, walnuts, hazelnuts and brazil nuts. Children often have allergies to milk and eggs as well as to peanuts, other nuts and fish.
Food intolerances are far more common than food allergies. The symptoms of food intolerance tend to come on more slowly, often many hours after eating the problem food. Typical symptoms include bloating and stomach cramps.
It is possible to be intolerant to several different foods at once. This can make it difficult to identify which foods are causing the problem.
Food intolerances can also be difficult to tell apart from other digestive disorders that produce similar symptoms, such as inflammatory bowel disease, gastrointestinal obstructions or irritable bowel syndrome (IBS).
The best way to test intolerance and sensitivity to a specific food is to eliminate it from your diet for at least 4 weeks and start introducing it slowly back into your diet, to observe any reactions. You should do this preferably under the supervision of an allergy specialist, as there are many other factors that can influence the results of this test. The most common reactions to food you might be intolerant to are bloating, gas, headaches and bowel changes.
Testing for allergies and intolerances can be very helpful to manage certain unwanted symptoms, which, although not life-threatening, can make our life quite miserable. Once they are recognised, we can avoid the allergen or allergens that cause these auto-immune reactions and offer our bodies and our natural defences a rest.