What is the first treatment for anaphylaxis?

Anaphylaxis is a rapidly developing allergic emergency that can affect breathing, blood pressure, skin, and the digestive system. Adrenaline works quickly to reduce swelling in the airway, support circulation, and ease narrowing of the air passages. Antihistamines do not replace adrenaline because they do not treat the most dangerous breathing or circulation changes.

Use the person’s adrenaline auto-injector in the outer thigh as soon as anaphylaxis is suspected, following the device instructions. Call emergency services, say that anaphylaxis is suspected, and keep the person lying down with legs raised if this is comfortable. If breathing is difficult, they may sit with legs extended. Do not let them stand or walk. A second dose may be needed if symptoms continue or return and help has not arrived; follow the emergency operator’s advice. Hospital assessment is needed even if the person improves.

Seek emergency help immediately for sudden breathing difficulty, throat or tongue swelling, faintness, collapse, or symptoms affecting more than one body system after a possible allergen. These signs can worsen quickly. After recovery, arrange follow-up to identify triggers and discuss an emergency plan; allergy testing may be part of that assessment.

Ask which symptoms should prompt adrenaline, how to use and store your auto-injector, whether you need more than one device, and how allergy testing could help identify a trigger.