Angioedema refers to edema of the deep dermis and subcutaneous tissues. Angioedema episodes may be mediated by mast cells or bradykinin. The episodes could be idiopathic, in which the symptoms appear without any evident triggers, or stimulus-induced, in which they are induced by a specific stimulus or load.

The condition is accompanied by superficial urticaria in some cases. On the other hand, stimulus-induced angioedema is usually not accompanied by urticaria. Angioedema caused by bradykinin includes hereditary angioedema, angioedema due to acquired C1-INH wasting or loss of function in the context of blood disorders or autoantibodies, and drug-induced angioedema.

We report a case with recurrent angioedema that resulted in airway stenosis. Three unexplained episodes of laryngeal edema occurred over a period of two years and two tracheotomies were performed. During the third episode of laryngeal edema, nasal intubation was performed immediately after the onset. Initially, we suspected hereditary angioedema, but there were no apparent abnormalities in blood or genetic testing. The patient had stopped taking an angiotensin II receptor blocker three years ago, but has not had any more attacks over the eight-year period since the last episode. Cases of angioedema of undiagnosed cause should be followed up with caution. In cases of angioedema that progresses gradually on an hourly basis, the airway should be secured, even if there are only mildly abnormal findings.