What to expect from allergy testing for food allergy

A clinician will ask what you ate, how quickly symptoms appeared, which body systems were affected, and whether the same reaction happened again. A skin-prick test places small amounts of selected allergens on the skin, while a blood test measures food-specific antibodies. 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 your history still matters. If uncertainty remains, an oral food challenge may be discussed; this involves eating carefully measured portions in a medical setting with observation.

Bring a list of suspected foods, ingredients, reaction timing, symptoms, medicines, and previous test results. Do not deliberately eat a suspected trigger to prepare. Ask whether antihistamines or other medicines need to be paused, because some can affect skin testing; only change them with clinical instructions. Wear clothing that allows easy access to the forearm or back, and follow fasting or medication directions if a food challenge is planned.

After testing or eating a suspected food, seek emergency help for trouble breathing, throat or tongue swelling, faintness, collapse, or rapidly worsening symptoms. Widespread hives with vomiting, wheezing, or dizziness also needs urgent assessment. Follow your personalised emergency plan if you have one.

Which foods should be tested based on my history? Could my medicines affect the test? What does a positive result change in my diet? Would a supervised food challenge be useful, and what safety plan should I carry?