How long does allergy testing take to work for food allergy?

Skin-prick reactions are generally checked after a short observation period. Blood tests need laboratory processing and a later review. A positive result shows sensitisation to a tested food, but it does not automatically predict the severity of a reaction or prove that the food caused every symptom.

If the history and test do not agree, an allergy specialist may consider further assessment. A supervised oral food challenge, when appropriate, is performed in a controlled medical setting. It should never be attempted at home, particularly after swelling, breathing symptoms or a previous severe reaction.

Avoid the suspected food as advised and read ingredient labels carefully. Record what was eaten, the amount, how quickly symptoms began and which body areas were affected. Carry any prescribed emergency medicine and ensure people close to you know how to use it. Ask before changing antihistamines because they may affect some skin tests.

Seek emergency help for trouble breathing, throat or tongue swelling, repeated vomiting with other allergy symptoms, faintness or rapidly worsening symptoms after eating. Do not wait for test results. Arrange follow-up for recurring hives, vomiting, abdominal symptoms or mouth itching so the suspected food and other causes can be assessed.

When will my result be available, does it match my reaction history, and should I avoid related foods? Do I need an emergency action plan, and would supervised challenge testing be considered?