Severe allergic reaction (anaphylaxis)

When to see a doctor · 2 min read

Common triggers

• Foods, such as peanuts, tree nuts, shellfish, fish, milk and eggs
• Insect stings, such as from bees and wasps
• Medicines, such as some antibiotics
• Latex

Signs of anaphylaxis

Signs usually start within minutes, but can take longer. They can include:

• Swelling of the lips, tongue, throat or face
• Difficulty breathing, wheezing, a hoarse voice or trouble swallowing
• A feeling of tightness in the throat or chest
• Hives, itching or flushed skin (though skin signs aren't always present)
• Dizziness, fainting, a fast heartbeat, or feeling a sense of doom
• Stomach cramps, vomiting or diarrhoea

What to do

• Use an adrenaline (epinephrine) auto-injector if the person has one. Follow the instructions on the device.
• Call 911 or your local emergency number straight away, even if they start to feel better. Symptoms can return.
• Lay the person down with their legs raised, unless they're struggling to breathe, in which case help them sit up. Don't let them stand or walk suddenly.
• If they stop breathing, start CPR. The call handler can guide you.

Being prepared

If you've had a serious allergic reaction, see a doctor or allergy specialist. They can confirm the trigger, and may prescribe an auto-injector, show you how to use it and give you an action plan. Carry it with you, check the expiry date, and tell friends, family and colleagues where it is.

Milder reactions

Mild reactions, such as a few hives or an itchy mouth, can still be a warning. See a doctor to find the cause, and get emergency help if breathing or swallowing becomes difficult.

Sources

• MedlinePlus: Anaphylaxis
• NIAID (NIH): Food allergy
• MedlinePlus: Allergy