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RESEARCH PRODUCT

Hereditary Angioedema with Normal C1 Inhibitor Activity Including Hereditary Angioedema with Coagulation Factor XII Gene Mutations

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description

Recurrent angioedema of the skin is a commonly diagnosed clinical symptom that can be found in various clinical entities [1,2]. Some types of angioedema of the skin are associated with episodes of upper airway obstruction that may be life threatening. Death by asphyxiation from laryngeal edema is well known in hereditary angioedema (HAE) due to C1 inhibitor deficiency [3,4] and in recurrent angioedema induced by angiotensinconverting enzyme (ACE) inhibitors [5–9]. Therefore, it is important to determine the exact type of angioedema in each patient. In many patients angioedema is associated with urticaria. If relapsing urticaria occurs simultaneously or alternately with angioedema, both conditions are assumed to be symptoms of the same disease. This assumption is true in chronic idiopathic urticaria/angioedema, IgE-mediated reactions (to foods, drugs, insect toxins, and other substances), serum sickness, urticaria/angioedema induced by aspirin and nonsteroidal anti-inflammatory drugs (NSAIDS) or azo dyes and benzoates, and in reactions caused by substances that induce direct histamine release from mast cells. Recurrent angioedema may occur in patients without urticaria. In these cases various disease entities due to a number of different pathogenetic mechanisms have to be considered. Recurrent angioedema without urticaria can be due to an inherited or acquired C1 inhibitor deficiency [10–13] or may be induced by ACE inhibitors. HAE due to C1 inhibitor deficiency is not associated with urticaria, whereas ACE inhibitors may cause recurrent angioedema alone or in association with urticaria. Other types of angioedema without urticaria