Print

What to Do If Someone Has an Allergic Reaction

Information provided is not a substitute for professional medical advice and you always seek appropriate professional help or seek immediate medical attention for serious conditions. See full disclaimer here

🌸 What to Do If Someone Has an Allergic Reaction

Allergic reactions can range from mild itching or swelling to life-threatening anaphylaxis.
Knowing how to recognise the signs β€” and when to act fast β€” can save a life.


⚠️ What Is an Allergic Reaction?

An allergic reaction happens when the body’s immune system overreacts to something harmless, such as:

  • Certain foods (nuts, dairy, shellfish, etc.)

  • Insect stings or bites

  • Medicines

  • Latex or chemicals

Reactions can appear within seconds or minutes of exposure, and the severity varies from mild to severe.


🀧 Mild to Moderate Allergic Reactions

Common signs:

  • Itchy skin or rash (hives)

  • Swelling of the face, lips, or eyes

  • Tingling mouth or lips

  • Sneezing or runny nose

  • Stomach cramps or vomiting

βœ… What to Do

  1. Stay calm and reassure the person.

  2. Remove or avoid the trigger if known β€” for example, move away from a bee or stop eating the suspected food.

  3. Let them take their own antihistamine if they carry one and can swallow safely.

  4. Apply a cold compress to reduce swelling or itching.

  5. Monitor their breathing and condition β€” even mild reactions can sometimes get worse.

If symptoms worsen or breathing becomes difficult, treat it as anaphylaxis.


🚨 Severe Allergic Reaction (Anaphylaxis)

Anaphylaxis is a life-threatening medical emergency.
It happens when the body reacts so strongly that airways narrow and blood pressure drops.

Signs of Anaphylaxis

  • Difficulty breathing, noisy breathing, or wheezing

  • Swelling of the tongue or throat

  • Difficulty speaking or swallowing

  • Pale, clammy skin

  • Weak, rapid pulse

  • Dizziness or collapse

  • Confusion or loss of consciousness


πŸš‘ What to Do Immediately

  1. Call 999 or 112 straight away

  2. Help them use their adrenaline auto-injector (EpiPen, Jext):

    • You may assist the patient – Read the instructions or follow the ambulance call handlers advice and guidance

    • Remove the cap.

    • Press the injector firmly into the mid-thigh (through clothing if necessary).

    • Hold for 5 seconds, then remove and massage the area for 10 seconds.

  3. if symptoms don’t improve within 5 minutes β€” they may need a second dose.

  4. Help them sit upright if breathing is difficult, or lie them down with legs raised if they feel faint.

  5. Loosen tight clothing and keep them calm.

  6. Monitor their breathing and response until paramedics arrive.

If they become unresponsive and stop breathing, start hands-only CPR β€” see How to Perform CPR.


πŸ’‘ After an Allergic Reaction

  • Even if symptoms improve after adrenaline, the person must still go to hospital β€” reactions can return. Do not cancel the ambulance.

  • Encourage them to carry both thier auto injectorsΒ at all times.


🌼 Preventing Allergic Reactions

  • Check food labels carefully.

  • Inform schools, colleagues, and friends about known allergies.

  • Keep auto injectors in date and accessible.

  • Wear a medical alert bracelet if appropriate.

  • Learn how to recognise early warning signs β€” especially in children.


Learn How to Respond with DAC Education

Our First Aid, Paediatric, and Emergency Response courses include full training on recognising and managing allergic reactions and anaphylaxis.
Learn to use auto-injectors confidently and stay calm when every second matters.

πŸ‘‰ Book a First Aid Course
(Delivered at our Suffolk HQ or on-site for groups of six or more.)


Disclaimer

This article provides general first aid guidance. Always call 999 or 112 if someone shows signs of a severe allergic reaction, even if they have used their adrenaline injector.

Table of Contents