In support of Rare Disease Awareness Month and Rare Disease Day, we are proud to share this article spotlighting hereditary angioedema (HAE), a rare and often misunderstood condition that can cause unpredictable and potentially life-threatening swelling episodes.
At Porterhouse, we believe awareness is a critical step toward earlier diagnosis, better support, and improved outcomes for patients and families living with HAE.
What is hereditary angioedema?
Hereditary angioedema (HAE) is a rare, inherited disease characterized by unpredictable recurrent swelling attacks of the extremities, genitals, abdomen, face, and/or airway. These attacks are painful, can affect patients’ appearance, and lead to diminished quality of life; attacks may even be fatal if the upper airway is affected.[1] HAE is believed to affect 1 in 50,000 people worldwide and occurs in both children and adults. [2]
What causes HAE?
In the most common type of HAE, a mutation in the SERPING1 gene causes deficiency or dysfunction in a blood protein called C1-esterase inhibitor. A lack of this inhibitor causes uncontrolled production of bradykinin and leads to ‘increased leakiness’ of blood vessels. As fluids move from within the blood vessels to the tissues, the typical HAE swelling ensues.[1] There are also types of HAE caused by mutations in genes associated with other blood factors, although these are less common. About 25% of patients with HAE will have a de novo mutation, where the mutation happens by chance and was not inherited from a parent.[2]
How is HAE treated?
Patients with HAE must always have access to medications to treat acute attacks, owing to the risk of swelling in the upper airways. Most of these on-demand medications are given by injection since they need to act quickly. [1] Some patients also choose to take preventive medications to avoid attacks or reduce their severity. These long-term prophylactic medications have the potential to improve patient outcomes and enhance quality of life.[2]
How does Porterhouse Medical support people with HAE?
As a global medical communications agency, Porterhouse Medical supports people living with HAE by collaborating on high-quality scientific publications from pivotal clinical trials in both adults and children. Through these efforts, we help ensure that robust clinical evidence is accessible to the global medical community. In addition, congress activities, graphical abstracts, and other educational initiatives are used to communicate the latest data in clear, engaging formats. Together, we are proud to help inform and empower patients, caregivers, and physicians with timely, evidence-based insights.
How can I help?
If you’d like to learn more about HAE, you can visit the US Hereditary Angioedema Association or HAE International for more information.
References
1, 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. Accessed April 2026
2, Bork K, Anderson JT, Caballero T et al. Assessment and management of disease burden and quality of life in patients with hereditary angioedema: A consensus report. Allergy Asthma Clin Immunol 2021; 17 (1): 40. Accessed April 2026
Author
Amanda Weber Ι Senior Medical Writer Ι Porterhouse Medical US
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