What should you know about food allergies and intolerances?

A food allergy involves an immune reaction, while an intolerance usually causes digestive symptoms without that immune response. Both can be uncomfortable, but an allergy can become an emergency and should not be self-diagnosed from symptoms alone.

Allergy symptoms may begin soon after exposure and include hives, swelling, wheezing, vomiting or an itchy throat. Intolerance may cause bloating, cramps, diarrhoea or nausea, often after a larger amount of a food. The same food can cause different reactions in different people, and symptoms may have another explanation. A clinician can review the pattern and consider allergy testing when appropriate.

Write down the food, amount, timing, preparation, symptoms and how long they lasted. Do not remove several food groups without advice, because unnecessary restriction can make balanced eating difficult. Until assessed, avoid a food that has caused a clear reaction and check labels carefully. Ask about a personal emergency plan if an allergy is suspected.

Call emergency services immediately for trouble breathing, throat or tongue swelling, faintness, collapse, or symptoms affecting more than one body system after eating. These may indicate anaphylaxis. Use prescribed emergency treatment as instructed while help is coming. A mild, isolated symptom still deserves clinical advice if it recurs.

Ask whether the pattern sounds allergic or intolerant, whether testing is useful, what foods need avoiding, how to read labels, and what to do if accidental exposure happens. Bring your symptom record and details of any previous reaction.