Angioedema
Overview
Angioedema is sudden, localized swelling of the deep dermis, subcutaneous tissues or mucosa caused by increased vascular permeability. It most commonly affects the face, lips, tongue and upper airway but may also involve extremities or the gastrointestinal tract.
Airway involvement can progress rapidly and is potentially life‑threatening - airway assessment and early senior involvement are priorities in the emergency department (ED).
Key clinical summary
- Two mechanistic groups determine immediate management: histamine (mast‑cell/IgE)‑mediated versus bradykinin‑mediated angioedema.
- Histamine‑mediated (allergic/anaphylactic) angioedema:
- Usually rapid in onset.
- Frequently associated with urticaria and pruritus.
- Responds to IM adrenaline, antihistamines and steroids as part of anaphylaxis care (Resuscitation Council UK; NICE CG134).
- Bradykinin‑mediated angioedema (ACE‑inhibitor associated, hereditary or acquired C1‑INH deficiency):
- Typically lacks urticaria/pruritus.
- Does not reliably respond to adrenaline/antihistamines/steroids.
- Requires stopping any offending drug, close airway management and consideration of bradykinin‑targeted or C1‑INH therapies under local/specialist guidance (NICE advice on ACEi angioedema).
Pathophysiology (concise)
- Histamine‑mediated: mast‑cell activation (IgE or non‑IgE) leads to histamine and other mediators causing increased microvascular permeability in more superficial dermal and submucosal tissues; often part of systemic anaphylaxis.