What is Anaphylaxis?

Anaphylaxis is the occurrence of a severe allergic reaction that is triggered when a person's immune system detects harmful / potentially harmful proteins (allergens) and responds defensively. Symptoms can start within minutes of exposure to an allergen, but can take up to several hours in some cases. In either case, anaphylaxis should be treated seriously as it can be fatal if not treated appropriately.


Signs & Symptoms

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 look out for any of the signs of a severe allergic reaction. Symptoms of a severe allergic reaction can include any of the following1:

  • Subjective general symptoms
    • Restlessness
    • Abnormal tiredness in children
    • Paresthesias or itching of palms, soles of feet, or in anogenital region
    • Metallic or fishy taste in the mouth
    • Visual disturbances
    • Feelings of anxiety
  • Skin
    • Generalized pruritus (severe itching)
    • Disseminated weals (hives)
    • Circumscribed tissue angioedema (localized swelling, e.g. of the eyelids, lips)
    • Episodic reddening (flushing)
  • Gastrointestinal tract
    • Nausea, vomiting
    • Stomach cramps, colic
    • Diarrhea, voiding of feces and/or urine
  • Airways
    • Rhinoconjunctivitis (irritated nose and eyes)
    • Dyspnea (shortness of breath)
    • Wheezing
    • Asthma attack
    • Blocking of upper trachea, glottal edema (a feeling of obstruction of the throat)
    • Respiratory arrest
  • Cardiovascular system
    • Palpitations and tachycardia (fast heart rate)
    • Drop in blood pressure
    • Collapse, circulatory shock, cardiac arrhythmia


First-Aid for Anaphylaxis

A severe allergic reaction can be life threatening. It is important to respond quickly and follow 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)

NB: All Alberta schools are required to have EpiPen® or Allerject™ auto-injectors on hand. School staff should have a regular replacement program per annual expiration dates.


Preventing Anaphylaxis

Most students are aware of existing allergies, particularly to more common allergens such as:

  • Food - nuts, fruit
  • Environment - pollen, plants, insects
  • Animals - cats, dogs

Efforts should be made to avoid or limit exposure to these allergens.

Adapted from:
Severe Allergic Reaction (Anaphylaxis). HealthLink BC.
1 Ring, J., Klimek, L. & Worm, M. Adrenaline in the acute treatment of Anaphylaxis. Dtsch Arztebl Int. 2018; 115:528-35.


Last revised on 20 September, 2023.