Pediatric hereditary angioedema.

Hereditary angioedema (HAE) is a lifelong illness characterized by recurrent swelling of the skin, intestinal tract, and, ominously, the upper airway. It is caused by inadequate activity of the protein C1-inhibitor, with dysfunction in the kallikrein/bradykinin pathway underlying the clinical symptoms. In addition to the physical symptoms, patients experience significant decrements in vocational and school achievement as well as in overall quality of life. Symptoms often begin in childhood and occur by age 20 in most patients, but life-threatening attacks are uncommon in the pediatric population. The availability of new therapies has transformed the management of HAE.