Emergencies
First Aid for Severe Allergic Reactions (Anaphylaxis)
30 Aug 2025

Intro
Anaphylaxis is a life-threatening allergic reaction that develops quickly. Early recognition and immediate epinephrine (adrenaline) can save a life. Always seek emergency care after treatment because symptoms can return.
Key Points
- Give epinephrine first, fast. Don’t wait to see if it improves.
- Call emergency services immediately after the first dose.
- Lay the person flat with legs raised; pregnant → left side; breathing trouble → sit up slightly.
- If no improvement in 5–10 minutes, give a second auto-injector (if available).
Recognize Anaphylaxis (any one of these after exposure to a likely allergen)
- Breathing problems: noisy breathing, wheeze, throat tightness, hoarse voice.
- Circulation problems: pale/clammy, faintness, weak pulse, collapse.
- Skin/gut symptoms plus breathing/circulation signs: widespread hives/flush, swelling of lips/tongue/face, severe tummy cramps/vomiting.
- Rapid onset minutes to (less commonly) hours after food, stings, meds, latex, etc.
What To Do — Step by Step
- Use an epinephrine auto-injector now.
- Inject into the outer mid-thigh through clothing if needed.
- Hold in place per device instructions (usually ~3 seconds).
- Call emergency services immediately (even if symptoms improve).
- Position
- Lay flat, legs raised.
- Breathing trouble: semi-reclined (avoid standing/walking).
- Pregnant: left side.
- Second dose if not improving in 5–10 minutes (use a second auto-injector).
- Monitor airway & breathing. Be ready to start CPR if needed.
- Avoid giving food/drink. Do not rely on antihistamines or inhalers instead of epinephrine.
Aftercare & Observation
- Must be observed in hospital; biphasic reactions can occur hours later.
- Record time(s) of injection and device type for clinicians.
- If stung, scrape off the stinger; apply cold pack for pain/swelling.
Auto-Injector Tips
- Common brands: EpiPen, Jext, Auvi-Q (device instructions vary—practice with a trainer).
- Dosage (typical):
- Children 7.5–25 kg: 0.15 mg
- ≥25–30 kg and adults: 0.3 mg (some adults may be prescribed 0.5 mg)
Follow the device prescribed by a clinician.
- Check expiry dates and store at room temperature (avoid heat/light).
Prevention & Planning
- Identify triggers (foods, stinging insects, meds, latex).
- Carry two auto-injectors at all times if prescribed.
- Wear medical ID; share an action plan with family, school, or workplace.
- Ask about allergen immunotherapy (e.g., venom) if appropriate.
FAQ
Can antihistamines replace epinephrine?
No. They may help itch/hives but do not treat airway or circulation problems.
What if I’m not sure it’s anaphylaxis?
If in doubt, use epinephrine. The risk of giving it unnecessarily is low; delay is dangerous.
Asthma + food allergy — higher risk?
Yes. Poorly controlled asthma increases risk for severe reactions; ensure asthma is well managed.
Further Reading
Related Guides
- #anaphylaxis
- #epinephrine
- #EpiPen
- #allergy
- #first aid