Testing for food allergies in adults

A clinician will ask what you ate, how much you had, how quickly symptoms began, and whether the same pattern happened again. They may ask about hives, swelling, vomiting, wheezing, mouth symptoms, or faintness. A skin-prick test places small amounts of selected allergens on the skin; an allergy blood test measures immune sensitisation to chosen foods. A positive result shows sensitisation, but it does not by itself prove that eating the food causes symptoms. A negative result can make an immediate allergy less likely, although the history still matters. Broad food panels can create confusing results, so testing is usually matched to a suspected food.

Keep a food and symptom diary with ingredients, timing, symptoms, medicines taken, and what happened next. Bring packaging or ingredient lists when a prepared food may be involved. Do not deliberately eat a suspected trigger at home to test it. Ask whether any antihistamines or other medicines need to be paused, because some can affect skin testing; follow the clinic's instructions rather than stopping treatment independently. If uncertainty remains, a specialist may discuss a supervised oral food challenge, where carefully measured food is given with observation and emergency treatment available.

After eating, sudden trouble breathing, throat or tongue swelling, widespread hives with dizziness, repeated vomiting, or collapse may indicate anaphylaxis. Use your prescribed adrenaline auto-injector if you have one and seek emergency help immediately. Do not wait for allergy testing during a severe reaction. For milder but recurring symptoms, arrange a clinical review so the suspected food and the pattern can be assessed safely.

Ask which food is being tested and why, whether the result can distinguish sensitisation from allergy, what medicines affect the test, and whether supervised challenge is appropriate. Ask for a written emergency plan if a reaction could be severe.