The diagnosis and treatment of hereditary angioedema patients in Japan: A patient reported outcome survey

Allergol Int. 2021 Apr;70(2):235-243. doi: 10.1016/j.alit.2020.09.008. Epub 2020 Nov 6.


Background: The rate at which patients are accurately diagnosed with hereditary angioedema (HAE), as well as diagnosed patients access to modern treatments differs greatly among countries. Moreover, the severity and burden of HAE on patients have been reported mostly on the basis of physician-reported surveys. To gain insight into the real-world conditions of patients with HAE through a patient-reported survey in Japan and identify any unmet needs.

Methods: A questionnaire was distributed to 121 patients with HAE via a Japanese HAE patient organization during 2016-2017. Responses were collected from 70 patients (57.9%) and subjected to analysis.

Results: The average periods from the initial appearance of symptoms (e.g. edema) to a HAE diagnosis was 15.6 years (min-max, 0-53). Patients visited an average of 4.6 different departments until receiving a definitive diagnosis. The average age at the first visit was 25.6 years (3-73) and at diagnosis 32.8 years (0-73). Patients reported an average of 15.7 (0-100) attacks per year, but only 53.1% of attacks were treated. The days of hospitalization due to severe attacks was 14.3 (0-200) before diagnosis, but these declined to 4.3 (0-50) after diagnosis. In the treatment for attacks, 82% of the patients were treated with the plasma-derived C1 inhibitor concentrate, and 69% of the patients reported experiencing a therapeutic effect.

Conclusions: There is a long gap between first attack and diagnosis of HAE, and the number of non-treated attacks is high in Japan. Steps are needed to improve the diagnostic and treatment environments to address these issues.

Keywords: Consultation behavior; Hereditary angioedema; Japan; Patient survey; QoL.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Angioedemas, Hereditary / diagnosis*
  • Angioedemas, Hereditary / drug therapy*
  • Angioedemas, Hereditary / prevention & control
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use
  • Antifibrinolytic Agents / therapeutic use
  • Child
  • Child, Preschool
  • Complement C1 Inhibitor Protein / therapeutic use
  • Complement Inactivating Agents / therapeutic use
  • Danazol / therapeutic use
  • Estrogen Antagonists / therapeutic use
  • Female
  • Hospitalization
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Patient Reported Outcome Measures
  • Steroids / therapeutic use
  • Surveys and Questionnaires
  • Tranexamic Acid / therapeutic use
  • Treatment Outcome
  • Young Adult


  • Anti-Inflammatory Agents, Non-Steroidal
  • Antifibrinolytic Agents
  • Complement C1 Inhibitor Protein
  • Complement Inactivating Agents
  • Estrogen Antagonists
  • Steroids
  • Tranexamic Acid
  • Danazol