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PrintWhat triggers a severe allergic reaction?
Learn about the ten priority food allergens that can cause a severe allergic reaction.
See which insects are most commonly associated with severe allergic reactions.
Find out which medications can cause a severe allergic reaction.
See what else can trigger a severe allergic reaction.
A severe allergic reaction is a reaction your body has to a particular trigger or “allergen.”
The most common triggers that can lead to a severe allergic reaction include:
Video: Triggers of a severe allergic reaction
Watch this video to learn about the most common triggers of a severe allergic reaction. This video also includes useful tips on how to avoid your triggers and what else you can do to be prepared.
Food allergies
Health Canada and the Canadian Food Inspection Agency (CFIA) have identified ten substances that are most frequently associated with food allergies and allergic-type reactions. These substances are often referred to as the ten priority food allergens.
The priority food allergens in Canada include:
- Peanuts
- Eggs
- Milk
- Tree nuts
- Wheat
- Soy
- Sesame seeds
- Seafood (e.g., fish, crustaceans and shellfish)
- Sulphites
- Mustard (new in August 2012)
Health Canada and the CFIA have recommended that these items be included on all product labels when they have been used as an ingredient or component of an ingredient.
People have been known to outgrow allergies to milk, soy and eggs after childhood, but peanut, tree nut and shellfish allergies tend to be lifelong.
Click here to visit the Health Canada website to access patient brochures on food allergies.
Back to topStinging and biting insects
The insects most commonly associated with severe allergic reactions belong to the Hymenoptera order of insects, also known as stinging insects. Stinging insects inject venom when they sting the skin, which can cause a severe allergic reaction.
Stinging insects include:
- Bees
- Wasps
- Yellow jackets
- Hornets
- Ants, including the fire ant
Biting insects (e.g., mosquitoes and black flies) are also associated with severe allergic reactions.
It is important to note that insect repellent does not prevent stings.
Back to topMedication
Both prescription and non-prescription drugs may cause an allergic reaction.
The medications that most often cause a severe allergic reaction include:
- ß-lactam antibiotics (including penicillin)
- Intravenous anesthetic drugs
- Opioid analgesics
- Aspirin
- Other noncorticosteroidal anti-inflammatory agents
Latex allergy
A latex allergy is an allergic sensitivity to the proteins in natural rubber latex (NRL). This reaction affects several systems throughout the body and often worsens with each exposure, potentially resulting in a severe allergic reaction.
Unlike synthetic latex, which rarely causes allergic reactions, NRL comes from the milky sap of rubber trees. Using various processing methods, NRL is used alone or in combination with other materials to make thousands of products including:
- Car tires
- Rubber bands
- Elastic
- Carpet backing
- Hospital and dental equipment
Dipped latex products are the biggest culprits in triggering allergic reactions, and include:
- Gloves
- Balloons
- Condoms
It is important to recognize that there is an association between reactions to latex and some foods. If you are allergic to latex, you may also notice a reaction to banana, avocado, kiwi, or chestnut. Tell your healthcare professional about any bad reactions you may have had to fruits and vegetables.
Back to topExercise-induced anaphylaxis
Some people experience an allergic reaction after they exercise. A severe reaction is known as exercise-induced anaphylaxis and is a form of physical allergy.
Why exercise causes a reaction is unknown. However, it appears that some medications [such as aspirin or non-steroidal anti-inflammatory drugs (NSAIDs)] or food consumed before and after exercise are factors that have been associated with experiencing exercise-induced anaphylaxis.
The reaction usually starts with skin symptoms such as itchiness or redness. If left untreated, it can lead to more serious gastrointestinal symptoms as well as swelling of the throat.
Back to topIdiopathic anaphylaxis
Sometimes a severe allergic reaction can occur without a known cause. This is called idiopathic anaphylaxis.
As with other types of severe allergic reactions, symptoms of idiopathic anaphylaxis include hives or skin swelling, wheezing, difficulty breathing, nausea, light-headedness, and fainting. However, most people don’t experience all of these symptoms at once.
A healthcare professional should try to rule out all other causes before making the diagnosis of
idiopathic anaphylaxis.
Should you be carrying an EpiPen®?
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