Emergencies

First Aid for Severe Allergic Reactions (Anaphylaxis)

Q: What is First Aid for Severe Allergic Reactions (Anaphylaxis)?

How to recognize anaphylaxis, use an adrenaline auto-injector, position the person, and what to do next.

2025-08-30

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.