HAE Attack Triggers

Patient-Reported Triggers3

Understanding Hereditary angioedema (HAE) triggers can help patients avoid those triggers.

Physical exertion involving a repetitive motion for long periods of time can place pressure on one part of the body that may induce an acute attack in HAE patients.

Mental stress can be a potential trigger for an HAE attack.3 HAE not only causes substantial short-term disability associated with attacks, but, in between attacks, patients may live in persistent anxiety and disappointment, being prevented from participating in selected activities. As such, patients experience substantial psychosocial burden living day-to-day with HAE.18 Mental health support or treatment may be necessary for certain individuals.3

Surgery, both medical and dental procedures, are examples of epithelial trauma. Dental surgery and tooth extractions can trigger the contact cascade, causing face, lip, cheek, laryngeal, and even abdominal edema.14

HAE symptoms can also be triggered by fluctuations in female hormones. The frequency of HAE attacks in women varies according to the different life stage—childhood, puberty, menses, pregnancies, and menopause. Combined oral contraceptives during the reproductive stage have also triggered HAE symptoms.15

While patients may be able to identify certain triggers, attacks do not always follow, making them difficult to predict.

Other Patient-Reported Triggers Include:

  • Infection
  • Weather changes
  • Menstruation
  • Medical/dental procedures
  • Food
  • Fatigue/exhaustion
  • Pregnancy
  • Estrogen-containing oral contraceptive use

Unpredictability of Attacks

A literature review related to the predictability of HAE attacks determined that HAE symptoms are not predictable in the long-term. While some patients may be able to predict some attacks in the short-term based on prodromal symptoms, the prevalence and characteristics of prodromes are highly variable. It is the unpredictability of HAE symptoms that causes anxiety about future attacks and impacts patients’ ability to maintain employment and otherwise be productive.17

How HAE Affects Patient Quality of Life2

Patients Report

  • Unable to consider certain careers/jobs
  • Impacts career advancement
  • Impacts educational choices
  • Hinders educational attainment

The US HAEA Medical Advisory Board recommends that all patients with HAE have access to at least two doses of acute, on-demand therapy for administration as early as possible when they feel the symptoms of an attack emerging.8

Role of On-Demand Therapy

Guidelines state on-demand treatment of attacks is most effective when administered early in the attack. Patients should be counseled to treat as soon as the attack is clearly recognized.4,8

The US HAEA Medical Advisory Board states that all attacks, irrespective of location, should be considered for treatment as soon as they are clearly recognized. Although there is overwhelming consensus that all abdominal, facial, oral, and upper respiratory attacks should be treated as early as possible, extremity attacks are also disabling and clearly worthy of early treatment to prevent dysfunction.8

Guidelines state patients who experience symptoms of laryngeal, tongue, or throat swelling should seek emergency medical care as soon as possible, even after initial self-treatment.4,8


  • [2] Lumry WR, Castaldo AJ, Vernon MK, Blaustein MB, Wilson DA, Horn PT. The humanistic burden of hereditary angioedema: Impact on health-related quality of life, productivity, and depression. Allergy Asthma Proc. 2010 Sep-Oct;31(5):407-14.
  • [3] Zotter Z, Csuka D, Szabó E, et al. The influence of trigger factors on hereditary angioedema due to C1-inhibitor deficiency. Orphanet J Rare Dis. 2014;9:44. https://doi.org/10.1186/1750-1172-9-44
  • [4] Maurer M, Magerl M, Betschel S, et al. The international WAO/EAACI guideline for the management of hereditary angioedema-The 2021 revision and update. Allergy. 2022;77(7):1961-1990.
  • [8] Busse PJ, Christiansen SC, Riedl MA, Banerji A, Bernstein JA, Castaldo AJ, Craig T, Davis-Lorton M, Frank MM, Li HH, Lumry WR, Zuraw BL. US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema. J Allergy Clin Immunol Pract. 2021 Jan;9(1):132-150.e3. doi: 10.1016/j.jaip.2020.08.046. Epub 2020 Sep 6. PMID: 32898710.
  • [14] Williams AH, Craig TJ. Perioperative management for patients with hereditary angioedema. Allergy Rhinol (Providence). 2015;6(1):50-55.
  • [15] Bouillet L, Longhurst H, Boccon-Gibod I, et al. Disease expression in women with hereditary angioedema. Am J Obstet Gynecol. 2008;199(5):484.e1-e4.
  • [17] Magerl MAK, Riedl MA, Newcomer SD, et al. The Predictability of Attacks in Patients with Hereditary Angioedema. J Allergy Clin Immunol. 2018;141(2):AB57.
  • [18] Bygum A, Aygören-Pürsün E, Beusterien K, Hautamaki E, Sisic Z, Wait S, Boysen HB, Caballero T (2015) Burden of illness in hereditary angioedema: a conceptual model. Acta Derm Venereol 95:706–710