Hereditary angioedema is a serious and rare autosomal dominant hereditary disease manifested by the formation of painless, nonpruritic subcutaneous and/or submucosal swelling. It is caused by a gene mutation resulting in an absolute or relative lack of C1 inhibitor (nonfunctional protein).
It occurs with a frequency of 1 : 50 000 to 1 : 10 000 in the population. The treatment of hereditary angioedema involves the use of three therapeutic strategies comprising long-term prophylaxis, short-term prophylaxis, and acute state treatment.
Long-term prophylaxis involves the use of oral esterase inhibitors (tranexamic acid) or anabolic steroids (attenuated androgen); in severe cases, regular intravenous administration of the C1-inhibitor Cinryze. Short-term prophylaxis with a purified C1-inhibitor concentrate (Berinert P, Cinryze, Ruconest) is necessary before traumatizing iatrogenic procedures.
The treatment of an acute state is essential when laryngeal obstruction, acute gastrointestinal complaints, or deforming skin edema develop. A bradykinin B2 receptor antagonist (icatibant - Firazyr) or a replacement with either plasma (Berinert, Cinryze) or recombinant (conestat alfa - Ruconest) C1-inhibitors are used.
A new and positive trend is early self-treatment of acute attacks by the patient themselves for which subcutaneous icatibant (Firazyr) can be used. Also available for home treatment are C1-inhibitors (Berinert, Cinryze, Ruconest) administered intravenously.
The decision on utilizing home treatment should be made individually for each patient by the attending physician who must provide appropriate instruction and check the technique of administration in certain intervals.