If you break out in a rash occasionally or have other allergy symptoms and you don't know the cause, you may want to consider being tested for food allergies. Food allergies are often difficult to detect because you may have a reaction right away, or the symptoms may not flare up for several hours after you eat the food. This leads to confusion about what is causing your symptoms. Your allergist can put an end to the guesswork by testing you for food allergies. Here are some things your doctor may try.

Skin Testing

Skin testing is a quick way to test for an allergic reaction to foods. Your doctor pricks your skin with a number of tiny needles that expose you to a variety of foods. If you are allergic to a certain food, you'll get a bump in the area it was applied. The results usually show up right away, so you will leave your doctor's office knowing what foods trigger your symptoms. Identifying your problem foods is the first step to managing your condition.

Blood Testing

Your allergist may also want to do a blood test for food allergens. This can be done along with the skin test as a way to verify the skin test results and catch any allergens the skin test missed. For this test, your doctor draws a vial of blood and sends it to a lab to be analyzed. It will take several days to get the results so your doctor may restrict your diet while you wait.

Challenge Testing

Even if you undergo skin and blood tests, your doctor may want you to do a challenge test unless your allergic reaction is so severe that you need to go on a strict avoidance diet. To do the challenge test, you start with an elimination diet that removes all suspected allergens from your menu. You avoid these foods as well as foods that are common allergens and see if your symptoms subside. If they do, you gradually add foods back into your diet and monitor yourself for the return of symptoms. You'll need to pay close attention to what you eat and keep a food diary that tracks what you eat and how you feel each day. This is a long and drawn-out process, but it can help you identify food allergies and food sensitivities that give you problems.

Uncovering your food allergies takes a bit of detective work, but once you know your trigger foods, you can avoid them so you stay symptom free. Since you may be allergic to a food additive rather than a whole food, you'll have to use caution when eating processed foods and when eating at restaurants so you aren't exposed to triggers unknowingly.