Anaphylaxis in a Sentence: What You Need to Know

The immune system releases chemicals after contact with a trigger such as a food, medicine, insect sting, or latex. The reaction can narrow the airways, swell the tongue or throat, and lower blood pressure. Symptoms may include wheezing, difficult or noisy breathing, throat tightness, a hoarse voice, persistent coughing, dizziness, confusion, collapse, vomiting, or widespread hives and swelling. Skin changes can occur, but their absence does not rule out anaphylaxis.

A reaction may begin soon after exposure and can worsen quickly. A person can also have different symptoms from one episode to another, so follow their personal allergy action plan when one is available.

Use the person's prescribed adrenaline auto-injector without delay, following the device instructions, and call local emergency services. Say that you suspect anaphylaxis. Adrenaline treats the dangerous effects on breathing and circulation; an antihistamine is not a substitute for it. If the person's action plan advises another dose because symptoms persist or return, use the additional prescribed injector as directed.

Keep the person lying flat with their legs raised. If breathing is difficult, they may sit with their legs extended, but they should not stand or walk. Place an unconscious person who is breathing on their side; begin CPR if they are not breathing normally and you know how. Stay with them and give used injectors to the ambulance team.

Treat sudden breathing difficulty, tongue or throat swelling, trouble swallowing, faintness, collapse, marked confusion, or reduced responsiveness after a possible allergen exposure as an emergency. Call for an ambulance even if adrenaline helps and the person seems better, because symptoms can return and further monitoring or treatment may be needed. Do not drive the affected person to care if an ambulance is available.

Ask what may have triggered the reaction, whether allergy testing or specialist assessment is appropriate, and which symptoms should prompt adrenaline use. Request a written emergency plan and hands-on practice with your auto-injector. Confirm where to inject it, how to check its expiry and viewing window, how many devices to carry, and what family members, school staff, or colleagues should do during another reaction.