The most common allergic disorder which requires hospitalization: Angioedema

Angioedema is a well-recognized side effect that may occur in patients taking angiotensin-converting enzyme inhibitors (ACEi).

Researchers analyzed angioedema hospitalizations (1998-2005). The angioedema hospitalization rate was 3.3 in 100,000 in 1998 and rose to 4.0 in 100,000 in 2005.

The total number of hospitalizations for non-angioedema allergic disorders declined during the same period and was surpassed by angioedema hospitalization rates after 2000.


ACE-inhibitor-induced angioedema affecting the upper lip (click to enlarge the images).

African American patients had double rate of angioedema hospitalizations compared to non-African American patients.

The authors concluded that angioedema has become the dominant allergic disorder that results in hospitalization in the United States.

Angioedema (AE) can be allergic or non-allergic.

There are 5 types of non-allergic angioedema (AE):

- acquired AE
- hereditary AE (HAE)
- ACE-inhibitor induced AE
- idiopathic AE, can occur with chronic urticaria
- pseudoallergic AE, e.g. reaction to NSAIDs

There are 3 types of HAE that are differentiated by C4 and C1-INH levels

- type I HAE - low C4, low C1-INH function, low C1-INH antigen level
- type II HAE - low C4, low C1-INH function, normal C1-INH antigen level
- type III HAE - all normal

Treatment of acute HAE attacks

- C1-INH, 20 units/kg, IV infusion
- Icatibant, 30 mg SC, bradykinin B2 receptor antagonist
- Ecallantide, 30 mg SC, kallikrein receptor antagonist

Prophylaxis of HAE attacks

- C1-INH, 1,000 units, IV infusion every 3-4 days
- attenuated androgen, e.g. danocrine 200 mg PO TID

References:


Increasing hospitalizations due to angioedema in the United States. Lin RY, Shah SN. Ann Allergy Asthma Immunol. 2008 Aug;101(2):185-92.
Angioedema Due to Angiotensin Converting Enzyme Inhibitors
Angioedema due to the renin inhibitor aliskiren. CCJM, 2011.
New Directions in the Treatment of Angioedema. Medscape, 2012.