title: Idiopathic nonhistaminergic angioedema.
abstract: OBJECTIVE
  We sought to describe the characteristics of a group of patients with idiopathic nonhistaminergic angioedema and their response to prophylactic treatment with tranexamic acid.
  
  
  METHODS
  We identified 25 patients (15 men and 10 women; age at diagnosis 16 to 77 years) who had idiopathic nonurticarial angioedema that was not prevented by histamine-1 (H1) blockers. Known causes of angioedema were excluded by clinical history, physical examination, and diagnostic tests.
  
  
  RESULTS
  The median age at the onset of symptoms was 35 years (range 8 to 66). The frequency of attacks was > 12 per year for 16 patients, six to 11 per year for 6 patients, and one to five per year for 3 patients. All patients had cutaneous attacks, 13 (52%) reported swellings of the pharynx or larynx, and 5 (20%) had symptoms consistent with bowel angioedema. Because of the similarities between these patients and patients who are deficient in C1 inhibitor, the 15 patients with severe and frequent attacks were started on prophylactic treatment with the antifibrinolytic agent tranexamic acid, 1 g three times a day orally for 3 months, tapered according to its effectiveness. The symptoms of 11 patients decreased to less than one attack per year, and the remaining 4 patients had partial remissions (less than 4 attacks per year). Fourteen patients are still being treated with tranexamic acid.
  
  
  CONCLUSIONS
  Patients with idiopathic nonhistaminergic angioedema appear to have similar clinical features and response to treatment with tranexamic acid as those who are deficient in C1 inhibitor. This suggests that those two forms of angioedema might have, at least in part, a similar pathogenesis.
authors.affiliation: Department of Internal Medicine, IRCCS Ospedale Maggiore, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cicardi
authors.forename: L
authors.initials: L
authors.lastname: Bergamaschini
authors.forename: L C
authors.initials: LC
authors.lastname: Zingale
authors.forename: D
authors.initials: D
authors.lastname: Gioffré
authors.forename: A
authors.initials: A
authors.lastname: Agostoni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000799:Angioedema / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D000933:Antifibrinolytic Agents / Q000627:therapeutic use; D003165:Complement System Proteins / Q000378:metabolism; D005260:Female; D006634:Histamine H1 Antagonists / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D014148:Tranexamic Acid / Q000627:therapeutic use
chemical_list: D000933:Antifibrinolytic Agents; D006634:Histamine H1 Antagonists; D014148:Tranexamic Acid; D003165:Complement System Proteins