Angioedema is sudden swelling of the deeper layers of the skin and mucosa, often of the lips, tongue, face or throat. It can be histamine-related (allergic, with hives) or bradykinin-related (ACE inhibitors, hereditary), and throat swelling can block the airway.
Key symptoms
- Swelling of the lips, tongue, eyelids or face
- Hives and itching in allergic forms
- Throat tightness, hoarse voice or trouble swallowing
- Abdominal pain attacks in hereditary angioedema
- Swelling that does not pit and is often uneven
What you find on exam
- Airway first: voice, stridor, drooling, ability to swallow
- Look inside the mouth: tongue, floor of the mouth, uvula
- Breathing rate, oxygen saturation, wheeze
- Blood pressure and skin for hives (signs of anaphylaxis)
Tests
- Diagnosis is clinical; never delay airway care for tests
- Review medications, especially ACE inhibitors
- C4 level, then C1 inhibitor level and function if hereditary angioedema is suspected
- Flexible laryngoscopy to view the larynx once stable
Treatment basics
- Secure the airway early if stridor or voice change
- Allergic or with anaphylaxis: IM epinephrine, antihistamines and steroids
- ACE inhibitor-related: stop the drug for good and watch the airway
- Hereditary: C1 inhibitor concentrate, icatibant or ecallantide
- Observe until the swelling stops progressing
Red flags
- Stridor, voice change or drooling
- Fast swelling of the tongue or floor of the mouth
- Low blood pressure or wheeze (anaphylaxis)
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Related guides
Sources: NASEMSO National Model EMS Clinical Guidelines; NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations. Written by Making Synapses. Making Synapses is not affiliated with these organizations.