Treatment of Angioedema

Introduction to Angioedema Treatment

The American College of Allergy, Asthma, and Immunology recommends that the treatment of angioedema depends on its type, with first-line therapies for hereditary angioedema (HAE) including plasma-derived C1 inhibitor, icatibant, or ecallantide, while histamine-mediated angioedema responds to antihistamines, corticosteroids, and epinephrine 1

Angioedema can be classified as hereditary angioedema (HAE), acquired C1 inhibitor deficiency, ACE inhibitor-induced, or allergic/histamine-mediated, with immediate assessment for airway compromise being critical 1
Diagnosis requires confirmation of recurrent angioedema without hives through clinical history, photos, and imaging evidence to differentiate true angioedema from factitious angioedema 2, 3
Detailed family history and medication history are essential, with special attention to ACE inhibitors which can precipitate attacks by decreasing bradykinin catabolism 4

For histamine-mediated angioedema, the American Academy of Allergy, Asthma, and Immunology recommends first-line treatment includes high-dose second-generation H1 antihistamines (fourfold the standard dose), with addition of montelukast if antihistamines alone fail 3
For bradykinin-mediated angioedema (HAE), the European Academy of Allergy and Clinical Immunology recommends first-line treatments include icatibant (30 mg subcutaneously) 1 and ecallantide (administered by healthcare provider within 8 hours of attack onset) 5

Standard angioedema treatments (epinephrine, corticosteroids, antihistamines) are NOT effective for HAE or ACE inhibitor-induced angioedema, which is a common treatment error in emergency settings 1
Laryngeal attacks are potentially life-threatening with historical mortality rates of approximately 30% or higher, requiring immediate medical attention following self-administration of medication 4, 6

Short-term prophylaxis before dental or surgical procedures includes plasma-derived C1 inhibitor (1000-2000 U intravenously) and androgens (danazol) 1
Long-term prophylaxis is recommended for patients with frequent attacks, with options including androgens (danazol 100 mg on alternate days) 1

Measure C4, C1INH antigen, and C1INH function to exclude C1INH deficiency 2, 7
If acquired C1INH deficiency is suspected based on age of symptom onset, C1q level and anti-C1INH antibodies should be measured 2, 7
For patients with suspected HAE with normal C1 inhibitor, targeted genetic screening may be necessary to identify pathogenic variants 2, 7, 3