Hereditary Angioedema

Publication Date: June 1, 2013

Key Points

Key Points

Most cases of hereditary angioedema (HAE) result from a deficiency of the serine protease inhibitor, C1 inhibitor (C1INH). (, LB)
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HAE is caused by mutations in the C1INH gene, resulting in a C1INH functional deficiency. (, LB)
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HAE is an autosomal dominant disease. Most patients with HAE have a positive family history of angioedema. (, A)
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Two forms of HAE, which are indistinguishable clinically, can be diagnosed by laboratory findings: type I HAE presents with low C1INH antigenic and functional levels, whereas type II HAE presents with normal C1INH antigenic levels but decreased C1INH functional levels. (, A )
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Diagnosis of type I or type II HAE requires evidence of low C1INH antigenic or functional levels, as well as decreased C4 levels and generally normal C1q levels. (, A)
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Onset of swelling in HAE most often begins during childhood and frequently worsens around puberty. (, C )
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HAE is characterized by relatively prolonged attacks of angioedema involving the extremities, genitourinary tract, abdomen, face, oropharynx or larynx. (, C )
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The primary mediator of swelling in HAE is bradykinin. (, A)
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Disease severity in HAE is highly variable, characterized by episodic rather than continuous swelling. (, D )
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A precipitating cause for most episodes of HAE attacks is unknown, but stress and trauma have been clearly recognized as precipitants. (, D)
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Attacks of swelling in HAE generally involve the extremities, abdomen, genitourinary tract, face, oropharynx, or larynx and follow a stereotypical pattern in which the swelling worsens over 24 hours, peaks, then slowly resolves over the following 48-72 hours. (, A )
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Attacks of HAE may be preceded by a prodrome. (, C )
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HAE attacks are associated with significant potential morbidity and potential mortality. (, A)
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Optimal management of HAE depends on early identification of patients. (, )
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Diagnosis

...gnosis

...able 1. Complement Levels in the Diagnosis of HA...


...Recurrent Angioedema – Diagnostic Alg...


Prevention

...reventio...

...ith replacement plasma-derived C1INH pr...


...agents for treatment of patients with C1IN...


...t with low to moderate doses of anab...


...with antifibrinolytic agents prov...


...hylaxis can be achieved with fresh frozen p...


...need for long-term HAE prophylaxis mu...


...and effectiveness of long-term prophylaxis should...


...strategies such as avoidance of ACE-Is,...


...action of 17α-alkylated androgen and antifibrino...


...ncy might be associated with an incr...


Treatment

Treatm...

...patients with HAE-specific agent. Evidence from d...


...of HAE attacks may involve symptomatic...


Fresh frozen plasma is often effective in abrogat...


...olic androgens nor antifibrinolytic drugs pro...


Epinephrine, corticosteroids and antihistam...


...2. HAE Treatment Algorithm...


.... HAE-Specific AgentsHaving trouble viewin...


...e 3. Drugs Commonly Used for Long-term HAE Pr...


Special Cases

...ecial Cases...

HAE with normal C1INH lev...

...recurrent angioedema characterized by no...

...s with HAE with normal C1INH levels appear to...

...C1INH levels may be caused by increased bradyki...

...veloped for patients with HAE with red...


...ed C1INH Deficiency...

...characteristics of angioedema episode...

...acquired C1INH deficiency involves dem...

Acquired C1INH deficiency results from enha...

...INH deficiency might be associated wi...

The treatment of acquired C1INH deficiency...


ACE-I–Associated Angioedema...

...are associated with angioedema in approximatel...

...ment of ACE-I (or ARB)–associated angioede...

...ngioedema associated with ACE-Is is likely due to...

...dest risk of recurrent angioedema exists in pa...