Anaphylaxis is a potentially life-threatening medical emergency that can occur when someone has a severe allergic reaction. Symptoms can develop within minutes and affect multiple body systems — from the skin to the respiratory and cardiovascular systems. Recognising the signs of anaphylaxis early and acting fast can save a life.
In this guide, we’ll explain what anaphylaxis is, its symptoms in adults and children, and the correct first aid response using an EpiPen. We’ll also explore how to prevent severe allergic reactions and where you can learn first aid in Australia.
What is an Allergy?
An allergy is when a person’s immune system reacts to triggers (allergens) that the person is hypersensitive to and is usually harmless to most other people. Symptoms of an allergy can range from mild to potentially life-threatening (severe). It occurs when the body mistakes something as harmful and creates a defence system (antibodies) to fight it.
The ways allergens can enter the body:
- Ingested (most common, in the mouth)
- Inhaled (breathed in)
- Injected (bees, wasps, ants or medication)
- Absorbed (through touching the skin)
- Allergy symptoms develop when the antibodies
are battling the “invading” allergen
What Is Anaphylaxis?
Anaphylaxis is a severe and sudden allergic reaction that occurs when the body’s immune system overreacts to a harmless substance, such as food like peanuts, insect venom, or medication. This overreaction triggers the release of chemicals that cause widespread inflammation, narrowing of airways, and a dangerous drop in blood pressure.
It’s considered a medical emergency that requires immediate treatment with adrenaline (epinephrine), typically delivered via an EpiPen. Without prompt intervention, anaphylaxis can progress rapidly and become fatal.
Anaphylaxis is potentially life-threatening and always requires an emergency response.
Common Symptoms by Body System
Symptoms of anaphylaxis can vary between individuals and may range from mild to severe. They typically affect multiple body systems simultaneously. Recognising these symptoms quickly helps you treat anaphylaxis fast.
Skin Symptoms (Hives, Swelling)
The skin often shows the first visible signs of an allergic reaction. Common symptoms include:
- Itchy hands, feet, or mouth
- Red, watery, or puffy eyes
- Swollen lips, face, or eyelids
- Hives or welts on the chest, armpits, or groin (these may look like insect bites)
While mild skin reactions can sometimes appear alone, hives can also signal the onset of anaphylaxis when accompanied by other symptoms such as breathing difficulty or dizziness.
Respiratory Signs (Wheezing, Throat Tightness)
Respiratory distress is one of the most dangerous features of anaphylaxis. Warning signs include:
- Difficulty breathing or shortness of breath
- Wheezing, coughing, or gasping for air
- Swelling or tightness in the throat or tongue
- Hoarse voice or difficulty speaking
As the reaction worsens, the airway can narrow, making breathing increasingly difficult. This is why adrenaline administration must happen immediately when these signs are observed.
Cardiovascular Warning Signs (Hypotension, Tachycardia)
Anaphylaxis can also affect the heart and circulation, leading to allergic shock. Cardiovascular symptoms may include:
- Pale, cool, or clammy skin
- Weak or rapid pulse
- Dizziness or light-headedness
- Sudden drop in blood pressure (hypotension)
- Loss of consciousness or collapse
In severe cases, cardiac arrest can occur. CPR should be started immediately if the person becomes unresponsive or stops breathing.
Gastrointestinal & Neurological Symptoms (Vomiting, Fainting)
The digestive system and brain may also be affected. Symptoms include:
- Stomach pain, nausea, vomiting, or diarrhoea
- Feeling anxious or having a sense of impending doom
- Confusion or altered mental state
- Fainting or becoming floppy (especially in young children)
Even mild gastrointestinal symptoms can quickly develop into severe anaphylaxis, so constant monitoring is crucial after an allergic reaction starts.
What is an EpiPen?
- An EpiPen is a small, hand-held, automatic injection device.
- It contains adrenaline and is injected into the fleshy part of the casualty’s thigh when experiencing an anaphylactic reaction.
- EpiPens are prescribed to people with known allergies and they may be able to inject themselves or may need assistance from the first aider
- Note: Single use only
Anaphylaxis Management Plan
Ensure that all patients prescribed an adrenaline auto-injector has an anaphylaxis management plan that includes:
- Referral to an appropriate specialist
- Identification of the relevant allergen(s)
- Education on avoiding allergen(s)
- An anaphylaxis action plan (see image)
- Appropriate follow-up and review
- Train patients to recognise the symptoms of
anaphylaxis and how to use their adrenaline auto-injector correctly
Where to Learn First Aid in Brisbane?
You can administer First Aid to someone who is experiencing a severe allergic reaction. If you are interested in enrolling in a first aid course in Brisbane, contact CPR First Aid for more information.
RTO No. 21903: CPR First Aid was founded in 2007. We specialise in providing first aid training, CPR training, childcare first aid courses, asthma and anaphylaxis courses for a range of workplaces including childcare, schools and other industries in NSW, VIC, SA, WA and QLD. We are a Registered Training Organisation with the Australian Skills Quality Authority (No 21903). Our courses and Units are VET-accredited for workplaces in Australia.
Recognising Anaphylaxis in Children
Children can experience anaphylaxis differently from adults. They might not always be able to describe their symptoms, making it important for parents, carers, and teachers to know the child anaphylaxis signs to watch for.
Common signs of anaphylaxis in children include:
- Sudden hives or swelling of the face, lips, or eyes
- Persistent coughing, wheezing, or hoarse voice
- Complaints of a “funny feeling” in the mouth or throat
- Vomiting, diarrhoea, or severe stomach pain
- Becoming pale, floppy, or unresponsive
If you suspect a child is having an anaphylactic reaction, use their EpiPen immediately and call 000. Even if symptoms appear to improve after adrenaline is given, they must still be taken to the hospital for monitoring. CPRFA’s Childcare First Aid course also equips you with the right skills to respond to emergencies.
What to Do When You Suspect Anaphylaxis
Knowing how to treat anaphylaxis fast can make the difference between life and death. Follow these anaphylaxis first aid steps:
- Follow DRSABCD – Check for danger, response, send for help, open airway, check breathing, start CPR if needed, and use a defibrillator if available.
- Lay the person flat. If breathing is difficult, allow them to sit upright but do not let them stand or walk.
- Remove the allergen if possible (e.g., flick out a bee sting).
- Administer adrenaline using an EpiPen. Inject into the outer mid-thigh. The EpiPen can be used through clothing if necessary.
- Call 000 immediately and state the person is experiencing anaphylaxis.
- Monitor breathing and consciousness. Be ready to perform CPR if needed.
- Give a second adrenaline dose after 5 minutes if symptoms do not improve or return.
- If unsure whether it’s asthma or anaphylaxis, use the adrenaline auto-injector first, then follow with asthma medication if required.
How to Use an EpiPen
- Remove the blue safety cap.
- Hold the orange end against the thigh.
- Push until you hear a click and hold for 3 seconds.
- Massage the injection site for 10 seconds.
EpiPens are designed for anyone to use in an emergency, even without medical training. After administering, stay with the person until medical help arrives.
Preventative Measures & First Aid Training
While anaphylaxis cannot always be prevented, understanding your triggers and being prepared can significantly reduce risks. Key prevention strategies include:
- Getting tested and identifying allergen triggers
- Avoiding known allergens and reading food labels carefully
- Keeping prescribed medications, including an EpiPen, accessible at all times
- Ensuring you and those around you are trained in first aid for anaphylaxis
Anaphylaxis Management Plan
Anyone prescribed an adrenaline auto-injector should have an Anaphylaxis Management Plan that includes:
- Referral to an allergy specialist
- Identification of relevant allergens
- Education on avoiding triggers
- A personalised Anaphylaxis Action Plan
- Regular review and update of the plan
- Training for family, friends, and colleagues on how to recognise and respond to anaphylaxis
Taking a first aid or CPR course equips you with the confidence and skills to respond effectively during a medical emergency.
Conclusion
Anaphylaxis is a serious, potentially fatal allergic reaction that requires immediate action. Recognising the early warning signs — such as swelling, breathing difficulty, or dizziness — and knowing how to use an EpiPen can save a life.
If you or someone you know has a severe allergy, always carry an EpiPen and ensure you have a clear anaphylaxis management plan. Learn how to respond confidently by enrolling in a first aid training course today.