Why does anaphylaxis cause wheezing?

A wheeze is produced when air passes through narrowed breathing tubes. During anaphylaxis, the muscles around those tubes can contract while swelling and mucus further reduce the space for airflow. Wheezing is a common presentation of Anaphylaxis. It may occur with coughing, chest tightness, breathlessness, hives, vomiting, facial swelling, or light-headedness.

Wheezing can also be caused by asthma, chest infections, inhaled irritants, and other conditions. When it starts after a likely allergy trigger or appears alongside throat or circulation symptoms, it needs emergency attention.

If anaphylaxis is suspected, use a prescribed adrenaline auto-injector immediately and call emergency services. Keep the person under observation. They should lie flat with legs raised if they can breathe comfortably, or sit with legs extended if breathing is difficult. Do not ask them to stand or walk.

A reliever inhaler can be used if it has been prescribed for asthma, but it is not a substitute for adrenaline in anaphylaxis. Further wheeze or deterioration requires emergency treatment.

Call emergency services for wheezing after food, medicine, an insect sting, latex, or another possible allergen, particularly with throat tightness, voice change, facial swelling, faintness, widespread rash, or repeated vomiting. Call urgently if the person cannot speak comfortably, becomes very sleepy, or collapses.

Ask what could have triggered the reaction, whether allergy testing is useful, and what to avoid until reviewed. Confirm when and how to use adrenaline, whether you need more than one device, and how people around you should respond if wheezing starts again.