A life-threatening severe allergic reaction can occur in anyone at any age, including people who have never shown any allergy symptoms before. That means you could be a potential first responder in an anaphylactic medical emergency, and your actions in the first few minutes shape what happens next.
What Counts as a Severe Allergic Reaction
Anaphylaxis is the medical name for a severe allergic reaction that affects breathing, circulation, or both. Mild to moderate allergic reactions stay at the level of skin and local tissue: hives, a tingling mouth, a swollen face, or an itchy rash around the area of exposure. Symptoms of anaphylaxis or exposure to an allergen include:
Difficult or noisy breathing
Swelling of the tongue
Swelling or tightness in the throat
Difficulty talking, or a hoarse voice
Wheeze, or a persistent cough with sudden onset
Persistent dizziness or collapse
Pale skin and floppy limbs (in young children)
Abdominal pain and vomiting, for insect sting or injected drug allergy
Any breathing change, any change in how blood moves around the body, or any loss of consciousness during an allergic reaction may be more serious than it appears and should be treated as anaphylaxis. For insect sting or medication allergies, abdominal pain and vomiting are also treated as severe signs as the substance has already spread through the bloodstream before reaching the gut.
Common Triggers of a Severe Allergic Reaction
A severe allergy is triggered by something that your immune system flags as dangerous. The most common allergen triggers are food, insect stings, and medications.
More than 170 foods can trigger allergic reactions. Ten items account for around 90% of food-related allergic reactions in Australia: milk, eggs, peanuts, tree nuts, sesame, fish, crustacea, molluscs, wheat, and soy.
Bee, wasp, and jack jumper ant stings cause most insect-related anaphylaxis in Australia, and fire ants, green ants, and ticks can also trigger a reaction.
Antibiotics (including penicillin), non-steroidal anti-inflammatory drugs like ibuprofen and aspirin, and some anaesthetics have all caused anaphylaxis. Herbal and complementary products can caused them too.
Less common triggers include latex, exercise, and cold temperatures.
The Adrenaline Injection Shot: First Aid for a Severe Allergic Reaction
Stay and call for help, and do not leave the person alone. If someone else is nearby, call them over to help and to fetch the adrenaline device if the person has one. If you are alone, keep the person in sight while you call triple zero (000).
Lay the person flat on their back. Do not let them stand or walk, even if they feel better. If they are unconscious, roll them onto their side, bend their top knee forward to stop them from rolling back, and tilt their head slightly back so their airway stays clear.
Adrenaline (epinephrine) is the first-line emergency treatment, delivered through an adrenaline autoinjector. Each one holds a single fixed dose and is designed for use without medical training. If the person has a medical history of anaphlyaxis this should be included in their allergy reaction plan.
Remove its safety cap, firmly press the injector into the middle of their outer thigh, through clothes if necessary, and hold it in place for the time marked on the device. Give them a second dose after 5 minutes if there is no improvement. Begin CPR if the person becomes unresponsive or their breathing is not normal.
Enrol in First Aid Training
Being able to identify a severe allergic reaction and respond to it in time is the difference between a near-miss and a death. The single factor that makes the biggest difference to outcomes is speed, and speed comes from practice under a trainer’s eye, where mistakes get corrected before they matter. A nationally recognised first aid course is how you become that prepared bystander. Your enrolment in first aid training is what separates merley being present from actually being useful when a severe allergic reaction happens.
FAQs
How Often is Asthma Mistaken for an Allergic Reaction?
The more common is the reverse: anaphylaxis mistaken for an asthma flare up. The cough in anaphylaxis is sudden, whereas an asthma cough can gradually build up as a tight chest and wheeze that responds to a puffer.
What Happens If You Use an Adrenaline Injector on Someone Who Does Not Need It?
The person may feel a racing heart, shakiness, or a headache for a short period, and those effects fade as the adrenaline clears. ASCIA’s position is that under-treating anaphylaxis is more dangerous than giving a dose that turns out to be unnecessary, because delayed adrenaline is associated with fatal reactions.
Can You Grow Out of a Severe Food Allergy?
Yes, sometimes. Children with allergies can grow out of them, though reassessment should be done by an allergy specialist rather than assumed at home.
