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

...agnosis...

...omplement Levels in the Diagnosis of HAEHaving t...


Figure 1. Recurrent Angioedema â€...


Prevention

Prevention

...nt with replacement plasma-derived C1IN...


...gents for treatment of patients with C1INH d...


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


...antifibrinolytic agents provides somewhat effect...


...ylaxis can be achieved with fresh frozen pla...


...r long-term HAE prophylaxis must be indiv...


...dose and effectiveness of long-term prophyla...


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


Mechanisms of action of 17α-alkylated androg...


...t be associated with an increase i...


Treatment

...atment...

...l patients with HAE-specific agent. Eviden...


...E attacks may involve symptomatic treatment...


...h frozen plasma is often effective in a...


...ther anabolic androgens nor antifibrinolytic drug...


..., corticosteroids and antihistamines are NOT...


Figure 2. HAE Treatment Algorithm


Table 2. HAE-Specific AgentsHaving tro...


...rugs Commonly Used for Long-term H...


Special Cases

...ial Cases...

...normal C1INH level

Familial recurrent angioedema characterized by...

...e kindreds with HAE with normal C1INH level...

...AE with normal C1INH levels may be caused by incr...

...d for patients with HAE with reduced C1INH func...


...red C1INH Deficiency...

...characteristics of angioedema episodes...

...gnosis of acquired C1INH deficiency involves dem...

...uired C1INH deficiency results from enhanc...

Acquired C1INH deficiency might be associated wi...

...ent of acquired C1INH deficiency is similar t...


...ssociated Angioedema...

...associated with angioedema in approxima...

...ent of ACE-I (or ARB)–associated angioedema...

...a associated with ACE-Is is likely due to i...

...f recurrent angioedema exists in patients who...