Allergy and intolerance tests: what to know

A result is useful only when it matches the reaction pattern and the suspected trigger. A positive test alone does not prove that exposure causes symptoms.

Skin-prick and specific-IgE blood tests look for sensitisation to selected allergens. Sensitisation means the immune system recognises a substance; clinical allergy means exposure also produces a compatible reaction.

Food intolerance does not usually involve the same immediate immune pathway. Symptoms may relate to digestion, dose, another ingredient, or a separate condition, so broad panels marketed as intolerance tests can be misleading.

Record what you ate or encountered, the amount, how soon symptoms began, and what happened afterward. Bring medicine names and photographs of any rash or swelling.

Do not stop antihistamines or other prescribed medicines unless the testing service gives specific instructions. Avoid removing several foods without clinical guidance, because unnecessary restriction can reduce dietary variety and obscure the true trigger.

Call emergency services for trouble breathing, throat or tongue swelling, faintness, collapse, confusion, or rapidly worsening symptoms affecting more than one body system after an exposure. Use prescribed adrenaline immediately if your emergency plan says to do so, then seek emergency help.

Arrange a clinical assessment for repeated reactions, symptoms after small amounts of food, poor growth, persistent digestive problems, or a diet that is becoming increasingly restricted.

Ask which suspected triggers should be tested, whether your history fits an immediate allergy or an intolerance, how medicines may affect testing, and what result would change your care. If food is involved, ask whether reintroduction or a supervised challenge is appropriate.