Quick read
Key points
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Anaphylaxis is a severe, potentially life-threatening allergic reaction that can develop within minutes of exposure to a trigger — commonly certain foods, insect stings, medications, or latex. It happens when the immune system releases a flood of chemicals that can cause the airway to narrow and blood pressure to drop suddenly.
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Topic-specific prevention and risk reduction will be added during the article-specific evidence audit.
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Always seek emergency care, even if symptoms improve after using an auto-injector — a second wave of symptoms can occur hours later
01 · Know
What is Anaphylaxis (Severe Allergic Reaction)?
Anaphylaxis is a severe, potentially life-threatening allergic reaction that can develop within minutes of exposure to a trigger — commonly certain foods, insect stings, medications, or latex. It happens when the immune system releases a flood of chemicals that can cause the airway to narrow and blood pressure to drop suddenly.
Anaphylaxis requires immediate treatment with adrenaline (epinephrine) and emergency medical care. People with known severe allergies are often prescribed an adrenaline auto-injector to carry with them at all times.
02 · Understand
Clinical context
Use an adrenaline auto-injector immediately if prescribed
If someone having a severe allergic reaction has a prescribed adrenaline auto-injector, use it right away and call emergency services — do not wait to see if symptoms improve on their own.
03 · Act
After Any Anaphylactic Reaction
- 1Always seek emergency care, even if symptoms improve after using an auto-injector — a second wave of symptoms can occur hours later
- 2Follow up with an allergy specialist to identify the trigger and discuss long-term management
- 3Ask about being prescribed (or renewing) an adrenaline auto-injector and getting trained on how to use it
- 4Discuss an allergy action plan for school, work, or travel
04 · Prevent & manage
Practical steps
This Is Not a Condition to Manage at Home
Anaphylaxis always requires emergency medical treatment. The steps below are what to do while waiting for help to arrive — they are not a substitute for calling emergency services.
- 1Call emergency services immediately.Do this before anything else, even if you plan to use an adrenaline auto-injector.
- 2Use an adrenaline auto-injector if available.Follow the device's instructions and administer it into the outer thigh as directed.
- 3Help the person lie flat.Raise their legs slightly if possible, unless they are having trouble breathing, in which case let them sit up in a position that's most comfortable.
- 4Be ready to give a second dose.If there is no improvement after 5–15 minutes and a second auto-injector is available, it may be used while waiting for emergency services.
- 5Stay with them until help arrives.Monitor breathing and consciousness continuously and be ready to perform CPR if they stop breathing or lose a pulse.
Medical information notice
Health education, not individual medical advice
BarnMD Health Library provides general health education for public health literacy. Reading this article does not establish a doctor-patient relationship and this information is not a diagnosis, prescription, or personalised treatment plan. If you have symptoms or concerns about your health, seek appropriate advice from a qualified healthcare professional. If you develop emergency warning signs, seek urgent or emergency medical attention.
BarnMD Bottom Line
Anaphylaxis can escalate very quickly, but prompt use of adrenaline and emergency care are highly effective at reversing it.
If in doubt, use the auto-injector and call for emergency help — acting fast saves lives.