Abstract and Introduction
Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.
Angioedema is a condition defined by non-dependent, non-pitting, transient edema lasting up to seven days due to the accumulation of vasoactive substances.[1–5] These substances increase vascular permeability, resulting in swelling in the deep dermal, submucosal, and subcutaneous tissues of the face, lips, neck, extremities, and gastrointestinal (GI) system.[1,2,6–9] Urticaria may be present in up to 50% of cases, depending on the underlying process.[1,2,6–9]
Angioedema accounts for 80,000 to 112,000 emergency department (ED) visits per year, with a hospitalization rate of 4.0 per 100,000 population.[10–12] For patients taking angiotensin-converting enzyme inhibitors (ACEi), the incidence of angioedema ranges from 0.1–0.7% over a patient's lifetime, while the prevalence of hereditary angioedema (HAE) ranges from 1 in 10,000 to 1 in 50,000 persons.[6,10–15] Over 50% of patients with HAE require ED management, with over half of patients admitted to the hospital.[1–3] ACEi-mediated angioedema accounts for 30% of angioedema cases. Of the cases of ACEi-mediated angioedema, one study found 18% of patients were admitted to observation, 12% to the inpatient setting, and 11% to the intensive care unit.[1,16] Due to risk of airway involvement and death, the emergency physician (EP) plays a key role in assessment and management of angioedema.[1,2,17,18]
Western J Emerg Med. 2019;20(4):587-600. © 2019 Western Journal of Emergency Medicine