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Acute HAE attacks and the emergency department

Patients with hereditary angioedema (HAE) suffer an emotional burden and experience unpredictable attacks that can impact their work and career in the long term, and may necessitate sudden visits to the emergency department. This article shares key insights into HAE emergency department visits.1–5

As HAE is a rare disease, even experienced healthcare professionals who make treatment decisions in emergency departments may be unaware of the best treatment for acute attacks:2

“One of the most severe attacks I had was in the genital area. It was so, so bad and painful that I actually went to my local hospital. They had been prewarned about me and had C1 in a fridge with my name on it. I was assured that when I turned up they’d know to treat me as an emergency. But no... Eventually, I got what was needed, but it took almost 2 hours.”3

— Tony, IT specialist and HAE sufferer

Urgent and prompt emergency care is needed for many patients with HAE. A 2014 study of 164 patients who had experienced an attack in the previous 6 months found that 23% sought medical care and more than half of these used their emergency department.1 Further studies highlighted the importance of emergency departments in the management of HAE3

In a study published in 2017, 99% of patients (104 of 105 included in the study) indicated that the understanding of HAE in the emergency department needed improving.3 Among those responding, 48% said the recognition of HAE as a diagnosis needed improving, 45% felt there needed to be greater appreciation of HAE as a serious disease and 59% said emergency departments needed to improve their management of medication.3

Adequate emergency treatment of HAE and specialist training on how to treat acute attacks are particularly necessary for C1 inhibitor activity–deficient HAE because it is rare, with an incidence of 1:50,000. Acute attacks can last from a few hours to several days and are unresponsive to antihistamines, epinephrine and corticosteroids.4 Of particular concern, laryngeal attacks can be life-threatening.4

National Health Service (NHS) guidelines state that prompt treatment is critical for acute HAE attacks and should not be delayed.5 In a 2020 review of emergency care for HAE has suggested that emergency departments should have a clear, visibly posted protocol or plan for triage and treatment based on established guidelines.4

Watch this HAE Burden of Illness mini clip to hear Tony talking about his experience.

Acute attacks can last between a few hours to several days and these attacks are unresponsive to antihistamines, epinephrine and corticosteroids.4 Laryngeal attacks can be life-threatening.4

  1. Aygören-Pürsün E, et al. Socioeconomic burden of hereditary angioedema: Results from the hereditary angioedema burden of illness study in Europe. Orphanet J Rare Dis 2014;9:99.
  2. Patient interviews. The emergency room and HAE. A film produced by Takeda for the Rare Disease Hub 2022. Available at: Accessed February 2022.
  3. Otani IM, et al. Emergency department management of hereditary angioedema attacks: Patient perspectives. J Allergy Clin Immunol Pract 2017;5:128–34.
  4. Pines JM, et al. Recognition and differential diagnosis of hereditary angioedema in the emergency department. J Emerg Med 2021;60:35–43.
  5. The NHS Leeds medicines formulary. Management of hereditary/acquired angioedema (HAE/AAE) - acute and prophylactic treatment product choices in adults 2020. Available at: Accessed February 2022.
Hereditary Angioedema
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February 2022