It turns out that diagnosis of food allergies based on blood or skin tests alone may be wrong, according to experts.

The gold standard of blood tests – the IgE antibody test – measures for the presence of IgE to a particular food. But it’s possible that you could have IgE and not actually have a reaction when you encounter that food.

Then there are skin prick tests, which are considered better predictors of allergy than blood tests. In this case, a small amount of the allergen is forced into the skin via a prick. Again, a reaction – the classic red wheal – does not mean that you’ll have an allergic reaction when you eat the food.

Apparently, the only way that some experts feel that you can really diagnose food allergy is to go through a food challenge in the doctor’s office. But the reality is that many would not want to take the risk of a severe reaction that proves the existence of the allergy.

So, it appears there is a gap between the tests and the ability to diagnose. This gap is filled by a careful history of the patient. A clear history of prompt reactions to a particular food is often the main factor in a diagnosis.

The trick appears to be the interpretation of tests – and not excluding foods too quickly, unless you’ve actually had a reaction to them. Tests alone should not dictate your diet. If your diet has become severely limited due to blood tests, consider a professionally monitored food challenge.

Source: Wall Street Journal