Factors associated with hospital admission in hereditary angioedema attacks: a multicenter prospective study.

Background: Acute attacks of hereditary angioedema are characterized by recurrent localized edema. These attacks can be life threatening and are associated with substantial morbidity and mortality.

Objective: To determine factors associated with hospital admission of patients with an acute attack of hereditary angioedema presenting at the emergency department.

Methods: This was a multicenter prospective observational study of consecutive patients (January 2011 through December 2013) experiencing an acute hereditary angioedema attack and presenting at the emergency department at 1 of 4 French reference centers for bradykinin-mediated angioedema. Attacks requiring hospital admission were compared with those not requiring admission.

Results: Of 57 attacks in 29 patients, 17 (30%) led to hospital admission. In multivariate analysis, laryngeal and facial involvements were associated with hospital admission (odds ratio 18.6, 95% confidence interval 3.9-88; odds ratio 7.7, 95% confidence interval 1.4-43.4, respectively). Self-injection of icatibant at home was associated with non-admission (odds ratio 0.06, 95% confidence interval 0.01-0.61). The course was favorable in all 57 cases. No upper airway management was required.

Conclusion: Most patients attended the emergency department because they were running out of medication and did not know that emergency treatment could be self-administered. Risk factors associated with hospital admission were laryngeal and facial involvement, whereas self-injection of icatibant was associated with a return home.