Severe Allergic Reaction (Anaphylaxis)

An allergic reaction occurs when a person’s immune system treats a protein (an allergen) in a food as harmful. Some children with food allergy are at risk of having a severe allergic reaction. A severe allergic reaction is very serious. It is also called anaphylaxis (an-nah-fil-axe-is). It often happens quickly and can cause death if not treated.

Symptoms of a severe allergic reaction (anaphylaxis)

Symptoms of a severe allergic reaction, called anaphylaxis, can start within minutes of eating or being exposed to an allergen or in some cases, the reaction can take up to several hours.

Symptoms can vary from person to person. The same person can have different symptoms each time they have a severe allergic reaction. An anaphylactic reaction can take place without hives, so make sure to look out for any of the signs of a severe allergic reaction. Symptoms of a severe allergic reaction can include any of the following:

  • Skin: hives, swelling (face, lips, tongue), itching, warmth, redness
  • Respiratory (breathing): coughing, wheezing, shortness of breath, chest pain or tightness, throat tightness, hoarse voice, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing), trouble swallowing
  • Gastrointestinal (stomach): nausea, pain or cramps, vomiting, diarrhea
  • Cardiovascular (heart): paler than normal skin colour/blue colour, weak pulse, passing out, dizziness or lightheadedness, shock
  • Other: anxiety, sense of doom (the feeling that something bad is about to happen), headache, uterine cramps, a metallic taste

Responding to a severe allergic reaction

A severe allergic reaction can be life threatening. It is important to respond quickly and appropriately by following these emergency steps.  

  1. Give epinephrine auto-injector (e.g. EpiPen® or Allerject™) at the first sign of a known or suspected severe allergic reaction
  2. Call 9-1-1 or your local emergency service. Tell them someone is having a severe allergic reaction
  3. Give a second dose of epinephrine as early as 5 minutes after the first dose if there is no improvement in their symptoms
  4. Go to the nearest hospital immediately (by ambulance if possible) even if symptoms are mild or have stopped. The reaction could get worse or come back, even after proper treatment. Stay in the hospital for observation for as long as the emergency department physician suggests (generally about 4 to 6 hours)
  5. Call emergency contact person (e.g. parent, guardian)

Other Important Information About EpiPen

  1. EpiPen products expire on the last day of the month indicated on the product packaging. For example, if the product is marked as expiring in January, it remains valid (not expired) until January 31
  2. You are advised to have more than one auto-injector with different expiry dates to avoid only having an expired auto-injector
  3. If you are experiencing an anaphylactic reaction and only have an expired auto-injector, use the expired product and immediately contact 9-1-1
  4. Whether the product is expired or not, go to the nearest hospital as soon as possible after using the product, as instructed in the product labelling

Food Allergies

Food can be an allergen for many people including the children and teens in our family. To learn more about recognizing and responding to severe food allergies in children and teens, including tips on how to help your child stay safe, see our HealthLink BC File #100a Severe Allergic Reactions to Food: Children and Teens.

Whether you or someone in your care has a food allergy, making food choices can be challenging. See our Food Allergies – Resources to learn more about how you can make healthy food choices for you and your family while managing food allergies.

Food Allergy Canada provides allergy information to educate, support, and advocate for the needs of individuals and families living with food allergy and the risk of anaphylaxis, as well as to support and participate in research related to food allergy and anaphylaxis. For more information on severe allergic reaction (Anaphylaxis), click on the links below:

Last Reviewed: August 1, 2018

The information provided in the Severe Allergic Reaction Health Feature has been adapted from the Anaphylaxis in Schools and Other Settings, Copyright 2005-2016 Canadian Society of Allergy and Clinical Immunology.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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