Quick answer
Hereditary angioedema (HAE) causes swelling that looks like a severe allergic reaction — but ASCIA is explicit that adrenaline, antihistamines and corticosteroids are not effective for HAE attacks. A paramedic who does not know you have HAE will reach for exactly those. A HAE medical ID says, in the first minute, “this is not anaphylaxis — use my HAE treatment”, and tells them where it is.
To a bystander, a swollen face, lips or throat means one thing: an allergy. The treatment for allergy is well known and drilled into first aiders and paramedics alike. For most people that instinct saves lives. For someone with hereditary angioedema it wastes time, because the swelling comes from a different mechanism and needs a different medicine. This guide explains what HAE is, why it is not anaphylaxis, when an attack is an emergency, and what your medical ID should say.
What hereditary angioedema is
HAE Australasia, the patient organisation for Australia and New Zealand, describes HAE as a rare inherited condition. People with HAE do not have enough working C1 inhibitor, a protein in the blood; as a result the body makes too much of a substance called bradykinin, and fluid leaks into the tissues, causing swelling. Its information brochure, based on the ASCIA position paper, notes estimates of how often HAE occurs range from 1 in 10,000 to 1 in 150,000 people, with about the same frequency in men and women.
Swelling can affect the limbs, trunk, face, genitals, gut or the upper airway. The brochure describes it as swelling without hives that is not itchy, which may start with tingling, can take around 24 hours to peak and resolves over 48 to 72 hours. Swelling in the gut can cause severe abdominal pain, nausea, vomiting and diarrhoea.
Why HAE is not anaphylaxis
| Allergic reaction / anaphylaxis | Hereditary angioedema | |
|---|---|---|
| Cause | An allergic trigger such as food, insects or medicine | Too little working C1 inhibitor, excess bradykinin; often no trigger at all |
| Hives and itch | Often | Swelling without hives, not itchy |
| Adrenaline | First-line emergency treatment | Not effective for HAE attacks, according to ASCIA |
| Antihistamines and steroids | Used for allergic reactions | Not effective for HAE attacks, according to ASCIA |
| What works | Adrenaline, then hospital care | Specific HAE medicines, often carried by the patient |
The ASCIA HAE Management Plan states it plainly in its first note: “Adrenaline, antihistamines and corticosteroids are not effective for HAE attacks.” The ASCIA position paper says the same. If you are not sure whether swelling is anaphylaxis, follow our anaphylaxis first aid guide — the point of a HAE medical ID is to remove that uncertainty before it arises.
When a HAE attack is an emergency
Airway swelling: call Triple Zero (000)
The ASCIA plan lists airway swelling as tongue or throat swelling, or difficulty breathing, talking or swallowing. Its instructions: phone an ambulance on 000, seek urgent hospital treatment, and give the person’s prescribed HAE medication.
For abdominal pain, the plan advises urgent hospital treatment if symptoms get worse or last longer than 24 hours.
The same plan notes that the patient’s own supply of HAE medicine should be used, at home or at hospital. ASCIA’s position paper explains that most people with HAE can be trained to self-administer treatment for acute attacks. That is why your record needs to say which medicine you carry and where it is: in an emergency, it may be the fastest effective treatment in the room. We do not give doses here; those are set by your immunologist.
Triggers, procedures and medicines
HAE Australasia notes that attacks often have no obvious trigger, but that stress, infection, injury, dental and other surgery, oestrogens and ACE inhibitors may trigger one. ASCIA’s position paper lists oestrogens including the oral contraceptive pill, hormone replacement therapy and pregnancy.
Procedures involving the mouth or throat, including intubation, carry an increased risk of airway swelling, and the brochure advises planning between the immunologist, surgical team and anaesthetists beforehand where possible. The ASCIA plan includes preventive treatment before invasive medical or dental procedures. An unplanned operation is exactly where a medical ID matters; our anaesthetic alert medical ID guide covers recording anaesthetic warnings.
Who reads a HAE medical ID
Australian resuscitation guidance tells responders to look. ANZCOR Guideline 2 includes, in the initial assessment of an emergency, checking for “physical (eg. alert jewellery) or electronic alert devices (eg. smartphone application) that may be relevant to assessment or management”. For HAE, that check changes the treatment:
- The bystander learns to find your HAE medicine rather than wait for an adrenaline injector.
- The paramedic learns that swelling without hives in you is HAE, and to prepare the airway early.
- The emergency team learns your immunologist’s name and which HAE medicine you use.
- The dentist or surgeon learns that preventive treatment is needed before the procedure.
What a HAE medical ID should say
On the band
- HEREDITARY ANGIOEDEMA
- NOT ALLERGY — ADRENALINE INEFFECTIVE — OWN HAE MEDICINE CARRIED
- Your membership number, so the rest can be read
In the profile
- Your HAE type and your ASCIA HAE Management Plan details.
- Your acute treatment: which medicine, how it is given, and where you keep it.
- Any long-term preventive treatment.
- Your known triggers, and medicines your immunologist has told you to avoid.
- Your immunologist and hospital, and an after-hours contact.
- Family members who have HAE or have been tested.
- Emergency contacts.
HAE, not allergy — your medicine, your plan, your immunologist, readable before adrenaline is reached for.
A MedibandPlus profile stores your HAE details, management plan, treatment location and contacts behind a membership number on a band you wear. No app, no login, from $19 a year.
Set up your profilePart of the Mediband family. Designed in Australia since 2004.
HAE runs in families
HAE Australasia describes HAE as autosomal dominant, which means a parent with HAE can pass it on to a child. If you have HAE, ask your immunologist whether your relatives should be tested, and record in your profile who in your family is affected. For children with HAE, make sure school and sport staff know the plan — and that adrenaline is not the answer for them.
Keeping it current
HAE treatment in Australia has changed in recent years, and ASCIA updated its position paper and management plan in 2022 to include newer treatments. Update your record whenever your treatment changes, after any attack that needed hospital care, and after every immunology review. For what to engrave on a band in general, see what to put on a medical wristband.
FAQs
What is hereditary angioedema?
A rare inherited condition in which the body does not have enough working C1 inhibitor, so it makes too much bradykinin and fluid leaks into the tissues. HAE Australasia describes recurrent swelling of the limbs, trunk, face, genitals, gut or upper airway, without hives and not itchy.
Does adrenaline work for hereditary angioedema?
No. The ASCIA HAE Management Plan states that adrenaline, antihistamines and corticosteroids are not effective for HAE attacks. Specific HAE medicines are needed, and the plan advises using the patient’s own supply at home or in hospital.
When is a HAE attack an emergency?
When there is airway swelling: tongue or throat swelling, or difficulty breathing, talking or swallowing. ASCIA’s plan says to phone an ambulance on 000, seek urgent hospital treatment and give the prescribed HAE medication. Abdominal attacks need urgent hospital care if they worsen or last longer than 24 hours.
How is HAE different from an allergic reaction?
Allergic swelling usually has a trigger and often comes with hives and itch, and adrenaline treats anaphylaxis. HAE swelling often has no obvious trigger, has no hives, is not itchy, builds over about a day and does not respond to adrenaline, antihistamines or steroids.
What can trigger a HAE attack?
Often nothing obvious. HAE Australasia lists stress, infection, injury, dental and other surgery, oestrogens and ACE inhibitors as possible triggers, and ASCIA lists oestrogens including the contraceptive pill, hormone replacement therapy and pregnancy.
Why do dentists and surgeons need to know about HAE?
Because procedures involving the mouth or throat, including intubation, increase the risk of airway swelling. HAE Australasia advises planning between the immunologist, surgeons and anaesthetists beforehand, and the ASCIA plan includes preventive treatment before invasive medical or dental procedures.
What should a HAE medical ID say?
On the band: “hereditary angioedema”, “not allergy – adrenaline ineffective”, that you carry your own HAE medicine, and a number that opens your record. In the record: your plan, acute and preventive treatment, where your medicine is kept, triggers, your immunologist and emergency contacts.
Sources
- ASCIA — Hereditary Angioedema Management Plan (2022) — emergency steps and the note that adrenaline, antihistamines and corticosteroids are not effective.
- ASCIA — HAE position paper — diagnosis, triggers and self-administered treatment.
- HAE Australasia — the patient organisation for Australia and New Zealand.
- HAE Australasia — About hereditary angioedema — how HAE works, prevalence, triggers and procedures.
- ANZCOR Guideline 2 — Managing an Emergency — checking for alert jewellery and devices.
Disclaimer: This article is general information about recording hereditary angioedema details for emergencies, not medical advice. Follow your ASCIA HAE Management Plan and your immunologist’s instructions. If you are unsure whether swelling is anaphylaxis, follow anaphylaxis first aid and call Triple Zero (000). In an emergency, always call Triple Zero (000). For non-urgent health advice, call healthdirect on 1800 022 222 (NURSE-ON-CALL 1300 60 60 24 in Victoria, 13 HEALTH 13 43 25 84 in Queensland).
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