What Is Anaphylaxis?
Anaphylaxis is a severe, life-threatening allergic reaction that can affect breathing, circulation, and multiple body systems at once. Without prompt first aid and treatment, it can be fatal within minutes. The most common triggers include certain foods, medications, insect stings, and latex, though any allergen can potentially cause a reaction in a sensitized individual.
Medical CauseWhy Does Anaphylactic Shock Occur?
When someone with an allergy comes into contact with an allergen, their immune system overreacts and releases a flood of chemicals — including histamine — into the bloodstream. In milder cases, this reaction stays localized to one area of the body, such as a skin rash or mild swelling. In more sensitive individuals, however, the reaction can escalate rapidly, affecting the airway, breathing, and circulation simultaneously. This full-body response is what defines anaphylaxis, and it requires immediate emergency care.
Symptom RecognitionRecognizing the Symptoms: Mild vs. Severe Reactions
Allergic reactions exist on a spectrum. Knowing the difference between a moderate reaction and a life-threatening one is critical to responding correctly and quickly.
Mild to Moderate Reaction
- Swelling of the face, lips, or eyes
- Hives or raised welts on the skin
- Tingling sensation in the mouth
- Stomach pain, nausea, or vomiting
Severe Reaction (Anaphylaxis)
- Difficult or noisy breathing
- Swelling of the tongue or throat tightness
- Difficulty talking or a hoarse voice
- Persistent wheeze or cough
- Dizziness, collapse, or loss of consciousness
- Pale, floppy appearance (especially in young children)
First Aid for a Mild to Moderate Allergic Reaction
If someone shows early or localized symptoms, act calmly but promptly to prevent escalation:
- Remove the insect sting if it is visible on the skin.
- Stay with the person at all times and call for help or medical advice.
- Administer a prescribed antihistamine for mild to moderate symptoms. If the reaction progresses to anaphylaxis, only adrenaline (epinephrine) is effective.
- Locate the person's adrenaline auto-injector (e.g., EpiPen) in case symptoms worsen.
- Contact a parent, guardian, or emergency contact immediately.
Emergency First Aid for Severe Anaphylactic Reaction
If you observe any signs of anaphylaxis, treat it as a medical emergency and act immediately:
- Lay the person flat. If breathing is difficult, allow them to sit up — but never let them stand.
- Administer the adrenaline auto-injector without delay.
- Call an ambulance immediately.
- Contact a parent, guardian, or emergency contact.
- If there is no improvement after 5 minutes and a second auto-injector is available, a further dose of adrenaline may be given.
If in Doubt, Give the Adrenaline Auto-Injector
- Adrenaline is life-saving and must be given promptly — delaying or withholding it can lead to rapid deterioration or death.
- Oxygen is usually administered once the person is in the ambulance.
- Medical observation in hospital for at least 4 hours is recommended after any anaphylactic episode.
- Common auto-injectors include EpiPen and Anapen. The green-labelled versions are generally prescribed for children aged 1–5 years.
