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Angioedema without urticaria
When isolated swelling is not necessarily an ‘allergy’
In this sheet
3 essential points
Isolated swelling is not automatically a food allergy
The lips, eyelids, tongue, face, hands, feet and sometimes the abdomen may be affected. The history and medicines taken are often more informative than a battery of allergy tests.
Without urticaria, the mechanism matters
Some forms are more likely histamine-mediated; others are bradykinin-mediated, including hereditary forms and some angioedema caused by angiotensin-converting enzyme inhibitors (ACE inhibitors).
Tongue, throat, voice or breathing: an emergency
Swelling that threatens the airway can be serious. Difficulty breathing or swallowing, a change in voice, swelling of the tongue or throat, or feeling faint: call 15 or 112.
What does angioedema look like?
The swelling is often deep, tense and sometimes asymmetrical. It may affect the lips or eyelids as well as other areas. Unlike a typical urticarial wheal, it may last longer and cause little or no itching.
Isolated swelling of the lips or eyelids is therefore not, on its own, proof of food allergy.
Two main mechanisms to distinguish
- Profile that may guide assessment
- More likely histamine-mediated
- Possible clues
- Itching or urticaria may be present, onset is often fairly rapid and an allergic context is possible; antihistamine treatment may help depending on the situation.
- Profile that may guide assessment
- More likely bradykinin-mediated
- Possible clues
- Usually without urticaria or itching, often slower and more prolonged, with possible abdominal pain; standard allergy treatments may have little effect.
| Profile that may guide assessment | Possible clues |
|---|---|
| More likely histamine-mediated | Itching or urticaria may be present, onset is often fairly rapid and an allergic context is possible; antihistamine treatment may help depending on the situation. |
| More likely bradykinin-mediated | Usually without urticaria or itching, often slower and more prolonged, with possible abdominal pain; standard allergy treatments may have little effect. |
These pointers cannot establish the diagnosis on their own. Atypical presentations exist, and an airway emergency is treated before the mechanism is known with certainty.
The important role of medicines: ACE inhibitors
Angiotensin-converting enzyme inhibitors (ACE inhibitors) are medicines used particularly for high blood pressure and some heart conditions. They can cause angioedema through bradykinin accumulation.
If a healthcare professional suspects ACE inhibitor-related angioedema, the treatment must be medically reassessed. Do not restart a suspected ACE inhibitor without explicit medical instructions.
What about hereditary forms?
Hereditary angioedema is a rare disease. It can cause repeated episodes of swelling without urticaria and sometimes abdominal pain; in some forms it is linked to a quantitative or functional C1-inhibitor abnormality.
A family history is a useful clue, but its absence alone does not rule out a hereditary form. Age at onset, circumstances and recurrence of attacks also matter.
The abdomen may be involved
In some bradykinin-mediated forms, swelling of the intestinal wall can cause attacks of abdominal pain, nausea or vomiting. Recurrent abdominal pain combined with unexplained swelling should be reported.
Which tests may be offered?
Assessment depends on the history. When hereditary or acquired bradykinin-mediated angioedema is suspected, the doctor may request complement tests such as C4 and C1-inhibitor measurement and function. Additional tests may be required depending on age and context.
Skin prick tests and IgE tests do not diagnose bradykinin-mediated angioedema.
During an attack: what matters first
Airway emergency
Swelling of the tongue or throat, a change in voice, difficulty breathing or swallowing, feeling faint or rapid worsening: call 15 or 112. Do not stay alone while waiting to see how it develops.
Adrenaline, antihistamines and corticosteroids: why responses may differ
In histamine-mediated angioedema or anaphylaxis, allergy treatments may have a role, and adrenaline is the first-line treatment for anaphylaxis when indicated.
In bradykinin-mediated angioedema, antihistamines, corticosteroids and adrenaline do not correct the underlying mechanism and may have little effect. Specific treatments exist for some forms and must be prescribed as part of a personalised plan.
Guidance for your care
If I already have an emergency plan
Follow the written plan provided by your team. A patient with IgE-mediated allergy or a risk of anaphylaxis may have different instructions from a patient monitored for bradykinin-mediated angioedema. The treatments are not interchangeable.
Oestrogens, pregnancy and medical procedures: situations to report
In some hereditary forms, hormonal factors or certain medical situations can alter attack frequency. If a hereditary form is known or suspected, report it before healthcare, a procedure, hormonal treatment or pregnancy so the team can adapt precautions if necessary.
Do not try to trigger an attack
There is no benefit in testing a food, medicine or other trigger yourself to ‘see whether swelling returns’. Diagnosis relies on the history, photographs, medicines and targeted tests when needed.
When should I seek advice outside an emergency?
- repeated episodes of swelling without urticaria;
- associated recurrent abdominal pain;
- a family history of unexplained swelling;
- taking an ACE inhibitor;
- attacks without a clear cause or not adequately explained by allergy;
- lack of response to prescribed standard treatment, especially when episodes recur.
Preparing for the consultation: what really helps
- What to record
- Where?
- Useful examples
- Lips, eyelids, tongue, throat, hands, feet, abdomen...
- What to record
- For how long?
- Useful examples
- Start time, total duration and progression of swelling.
- What to record
- With or without urticaria?
- Useful examples
- Itchy wheals? itching? no associated skin sign?
- What to record
- Medicines
- Useful examples
- Exact names, especially blood-pressure or heart medicines; how long have they been taken?
- What to record
- Other clues
- Useful examples
- Photographs, abdominal pain, family history and repeated circumstances.
| What to record | Useful examples |
|---|---|
| Where? | Lips, eyelids, tongue, throat, hands, feet, abdomen... |
| For how long? | Start time, total duration and progression of swelling. |
| With or without urticaria? | Itchy wheals? itching? no associated skin sign? |
| Medicines | Exact names, especially blood-pressure or heart medicines; how long have they been taken? |
| Other clues | Photographs, abdominal pain, family history and repeated circumstances. |
Common misconceptions
- Misconception
- ‘My lips swell, so it must be a food.’
- SOS Allergo guidance
- No. Several mechanisms are possible, including a medicine.
- Misconception
- ‘Without urticaria, it cannot be serious.’
- SOS Allergo guidance
- False. Angioedema of the tongue or throat can be an emergency.
- Misconception
- ‘My allergy tests are negative, so nothing is wrong.’
- SOS Allergo guidance
- Bradykinin-mediated forms are not diagnosed with skin prick tests or IgE tests.
- Misconception
- ‘I have taken my blood-pressure medicine for years, so it cannot be responsible.’
- SOS Allergo guidance
- False for ACE inhibitors: angioedema can occur late.
- Misconception
- ‘No family cases means no hereditary angioedema.’
- SOS Allergo guidance
- Family history helps, but its absence does not rule out every form.
| Misconception | SOS Allergo guidance |
|---|---|
| ‘My lips swell, so it must be a food.’ | No. Several mechanisms are possible, including a medicine. |
| ‘Without urticaria, it cannot be serious.’ | False. Angioedema of the tongue or throat can be an emergency. |
| ‘My allergy tests are negative, so nothing is wrong.’ | Bradykinin-mediated forms are not diagnosed with skin prick tests or IgE tests. |
| ‘I have taken my blood-pressure medicine for years, so it cannot be responsible.’ | False for ACE inhibitors: angioedema can occur late. |
| ‘No family cases means no hereditary angioedema.’ | Family history helps, but its absence does not rule out every form. |
Key points
- Angioedema without urticaria is not automatically a food allergy.
- Distinguishing histamine-mediated and bradykinin-mediated mechanisms can change assessment and treatment.
- ACE inhibitors are an important medicine-related cause to recognise.
- Recurrent abdominal pain may be part of some bradykinin-mediated forms.
- Tongue, throat, voice or breathing affected = emergency: call 15 or 112.
You may also want to read
Main references
- Maurer M, Magerl M, Betschel S, et al. The international WAO/EAACI guideline for the management of hereditary angioedema - The 2021 revision and update. Allergy. 2022;77(7):1961-1990. DOI: 10.1111/all.15214. PMID: 35006617.
- Papapostolou N, Gregoriou S, Katoulis A, Makris M. Five-Membered Nitrogen Heterocycles Angiotensin-Converting Enzyme (ACE) Inhibitors Induced Angioedema: An Underdiagnosed Condition. Pharmaceuticals (Basel). 2024;17(3):360. DOI: 10.3390/ph17030360.
- Dubrall D, et al. Non-genetic factors associated with ACE-inhibitor and angiotensin receptor blocker-induced angioedema. Clin Transl Allergy. 2025. DOI: 10.1002/clt2.70058.
General information: this sheet does not make a diagnosis and does not replace a consultation or personalised emergency plan. For swelling of the tongue or throat, a change in voice, difficulty breathing or swallowing, feeling faint or rapid worsening, call 15 or 112.
Scientific review: September 2026 · sosallergo.fr