Diagnosing anaphylaxis

Anaphylaxis is a sudden, severe allergic reaction that can affect breathing, circulation, skin, or the digestive system. Signs may include swelling of the lips or tongue, throat tightness, trouble breathing, wheezing, widespread hives, faintness, repeated vomiting, or collapse. Skin changes may be absent, so a person can still have anaphylaxis without a rash.

A clinician considers what happened just before symptoms began, how quickly they developed, which body systems were involved, and whether there was exposure to a possible trigger such as food, medicine, or an insect sting. The history is central; no immediate blood test can safely rule out the emergency.

Use an adrenaline auto-injector if one has been prescribed and anaphylaxis is suspected, then call emergency services. Lie the person down with legs raised unless breathing is easier sitting up; keep them still and do not let them stand or walk. A second injector may be needed if symptoms continue and local emergency advice supports it.

After recovery, arrange specialist follow-up. [Allergy Testing] may help identify a trigger, but testing should be planned after the acute event. Ask for a written emergency plan, injector training, and advice on avoidance. An [Anaphylaxis Emergency Treatment] service may explain observation and discharge planning.

Call emergency services immediately for throat or tongue swelling, breathing difficulty, [Wheezing], sudden faintness, collapse, or symptoms affecting several body systems after a possible allergen. Do not rely on an antihistamine alone for breathing or circulation symptoms. Symptoms can return after initial improvement, so follow emergency advice even when the person appears better.

Ask: What was the likely trigger? Do I need referral for allergy assessment? How do I use my auto-injector? Should I carry two devices? What should family, school, or colleagues do? Which foods or medicines need avoidance, and when is re-exposure unsafe?