Diagnosis

The discussion you and your doctor have about your symptoms and medical history starts the process of diagnosis. A physical exam usually follows this discussion. The next steps typically include some of the following:

• Food diary. Your doctor may ask you to keep a food diary of your eating habits, symptoms and medications.
• Elimination diet. If it isn't clear that peanuts are causing your symptoms, or if your doctor thinks you may have a reaction to more than one type of food, he or she may recommend an elimination diet. You may be asked to eliminate peanuts or other suspect foods for a week or two, and then add the food items back into your diet one at a time. This process can help link symptoms to specific foods. If you've had a severe reaction to foods, this method can't safely be used.
• Skin test. A small amount of food is placed on your skin, which is then pricked with a needle. If you're allergic to a particular substance, you develop a raised bump or reaction.
• Blood test. A blood test can measure your immune system's response to particular foods by checking the amount of allergy-type antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies.

Information from all these sources may help determine if you have a peanut allergy or if your symptoms are likely due to something else, such as food intolerance.