Anaphylaxis is a severe allergic reaction that can develop within minutes and can be life threatening. Common triggers include foods, medications, insect stings and latex. Sometimes the trigger is not identified.
Warning Signs
- Swelling of the tongue or throat
- Difficulty breathing, wheezing, persistent coughing or a hoarse voice
- Difficulty swallowing or a feeling that the throat is closing
- Sudden dizziness, confusion, collapse or loss of consciousness
- Pale, cold or clammy skin
A raised itchy rash, flushing, swelling of the lips or face, vomiting or abdominal pain may also occur. Anaphylaxis can happen without a skin rash.
Emergency Action
Contact your local emergency services immediately. If the person has an epinephrine auto-injector, use it at once according to their emergency plan and the device instructions. Do not delay while waiting to see whether symptoms improve.
Lay the person flat with their legs raised if possible. If breathing is difficult, they may sit up slowly. A pregnant person should lie on their left side. Do not let the person stand or walk. If symptoms continue and a second prescribed auto-injector is available, follow the person’s emergency plan and instructions from emergency services.
After Emergency Treatment
Hospital observation may be needed because symptoms can return. Follow-up with an allergy specialist may help identify the trigger and provide an emergency plan, avoidance advice and training in the use of epinephrine auto-injectors.
Sources and Further Reading
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical assessment or treatment.