Types of food allergy testing

A clinician first reviews what was eaten, how quickly symptoms began, which symptoms appeared, and whether the reaction has happened more than once. Skin prick testing places small amounts of suspected allergens on the skin, then checks for a local reaction. A blood test measures immune antibodies to selected foods. Either test can support an allergy diagnosis, but a positive result does not by itself prove that eating the food causes symptoms.

A supervised oral food challenge involves eating carefully measured portions while trained staff watch for a reaction. It can help confirm or rule out allergy when the history and other tests do not agree. Do not test foods at home if a previous reaction involved breathing difficulty, faintness or widespread swelling.

Keep a record of the food, ingredients, portion, timing and symptoms. Bring photographs of visible skin changes and a list of medicines, because some medicines can affect skin testing. Avoid removing several foods without professional guidance; broad restriction can make meals less balanced and can obscure the true trigger. An allergy clinician can explain whether a test for Food Allergy fits your history.

Call emergency services immediately for trouble breathing, throat or tongue swelling, severe dizziness, collapse, or symptoms affecting more than one body system after eating. These can be signs of Anaphylaxis. Testing is not a substitute for an emergency plan, and a person with a known severe allergy should follow the plan prescribed by their clinician.

Which foods should be assessed, and what does each proposed test measure? Could my medicines affect the result? Do I need a supervised food challenge, and what should I do if symptoms return before testing is complete?