What are the first signs of anaphylaxis?

The first signs of anaphylaxis may include sudden itching, hives, facial swelling, throat tightness, difficulty swallowing, wheezing, vomiting or faintness. Symptoms can progress quickly and may involve more than one part of the body.

Anaphylaxis is a severe allergic reaction. Early clues may follow food, a medicine, or an insect sting and can include widespread skin changes, swelling of the lips or face, coughing, noisy breathing, a tight throat, abdominal pain or repeated vomiting. Some people do not develop a rash. Feeling weak, pale, confused or faint can indicate that circulation is being affected. A previous mild reaction does not reliably predict how a later reaction will behave.

Use a prescribed adrenaline auto-injector straight away if anaphylaxis is suspected, following its instructions, and call emergency services. Lie the person down with legs raised unless breathing is difficult; allow them to sit with legs extended if that helps breathing. Do not let them stand or walk. If symptoms continue and another injector is available, use it according to the device instructions. Stay with the person until help arrives.

Treat sudden facial swelling, difficulty swallowing, breathing difficulty, wheezing, faintness or collapse after a possible allergen as an emergency. Do not wait to see whether symptoms settle and do not rely on antihistamines for breathing or circulation symptoms. Anyone treated for suspected anaphylaxis needs emergency assessment because symptoms can return.

After recovery, ask what may have triggered the reaction, how to use an auto-injector, whether you need allergy testing, and how to record and avoid the suspected trigger. Ask when replacement devices should be obtained.