First aid · · 2 min read
Anaphylaxis: warning signs and an emergency action plan
Anaphylaxis is a rapidly developing, dangerous allergic reaction. Breathing problems, tongue or throat swelling, collapse or fainting require emergency help. Call your local emergency number. A rash does not have to be present.
Act immediately
Use a prescribed adrenaline auto-injector according to its instructions and arrange emergency help. Say that anaphylaxis is suspected. Do not wait for an antihistamine tablet to work: it is not a substitute for adrenaline in this emergency.
Position and emergency support
Do not let the person stand or walk. Usually they should lie down; raise the shoulders carefully if breathing is difficult, and position a pregnant person on the left side. Follow the dispatcher. Start dispatcher-guided resuscitation if normal breathing stops.
If symptoms do not improve
NHS advice recommends a second auto-injector after 5 minutes without improvement. Follow the individual action plan and device instructions. Improvement does not remove the need for emergency medical assessment; do not cancel help independently.
Prepare before another reaction
Work with an allergy specialist on triggers, prescribed devices, storage and instructions for others. With food allergy, checking ingredients and informing food-service staff are important. Do not test a suspected trigger by deliberate exposure at home.
Your practical checklist
- Check expiry dates on prescribed auto-injectors.
- Practise with a trainer device.
- Show trusted people where the action plan is and when to call emergency services.
Questions and answers
Should I wait for a rash?
No. Dangerous breathing or consciousness changes require immediate action even without visible skin changes.
Can someone stand up once they feel better?
Do not stand or walk while awaiting assessment. Stay in a safe position and follow emergency-service instructions.
Sources
Sources checked on 26 September 2026.