Over the past several weeks I have had several questions about food allergy skin tests and/or blood tests and if they mean anything in terms of food reactions. I think the specific question that is being asked is does the size of the skin test or the degree of reaction of the blood test correlate to what type of reaction one could expect if exposed to the food in question and do either of these tests predict how much one must be exposed to before a reaction would occur. The short answer is no.
The size of a food allergy skin test reaction or the degree of positive reaction on the food allergy blood test does not predict what type of reaction that could occur if one is exposed to the food in question. If you have a history of reacting to a particular food and you have a positive food allergy skin test and /or blood test then you are at risk to reacting to that food in the future. A smaller test result does not mean that you may only have hives and a larger reaction does not mean you will have breathing problems, for example. If you have a history of an allergic reaction to a food and this confirmed by food allergy testing then you must avoid this food and obviously have an anaphylaxis treatment plan and an auto injectable epinephrine available for use.
Similarly, the size of the food allergy test result does not predict how little or how much of that food you would have to consume before a reaction would occur. A small test results does not mean that only a little bit of the food would be needed to cause a reaction.
Food allergy skin test “simply” confirm or refute your clinical history of reacting to a particular food.