Hereditary angioedema (HAE) is a rare inherited disorder causing recurrent of episodes of swelling that can be potentially life threatening. Treatment of HAE can be divided into on-demand treatment for swelling, and prophylaxis. The last UK consensus on HAE was in 2014 and since then, new medications for prophylaxis have been developed, with more drugs in the pipeline. International guidelines currently recommend the use of long-term prophylaxis (LTP) as the only way of achieving disease control and normalising patient lives. Modern prophylactic medications are available in the UK, although access is restricted primarily by HAE attack frequency. To establish an updated view of UK clinicians and patients, a Delphi process was used to develop statements regarding long-term prophylaxis as well as other aspects of HAE management. There was consensus that UK access criteria for modern LTP agents based on numerical frequency of attacks alone is too simplistic and potentially disadvantage a cohort of patients who may benefit from LTP. Additionally, there was agreement that patients should be seen in expert centres, remote monitoring of patients is popular post-pandemic, and that the use of patient reported outcome measures have the potential to improve patient care. Psychological health is an area in which patients may benefit, and recognition of this is important for future research and development.

Background: Detailed demographic data on people with hereditary angioedema and acquired C1 inhibitor deficiency in the UK are relatively limited. Better demographic data would be beneficial in planning service provision, identifying areas of improvement and improving care. Objective: To obtain more accurate data on the demographics of hereditary angioedema and acquired C1 inhibitor deficiency in the UK, including treatment modalities and services available to patients. Methods: A survey was distributed to all centres in the UK who look after patients with hereditary angioedema and acquired C1 inhibitor deficiency to collect these data. Results: The survey identified 1152 patients with HAE-1/2 (58% female, 92% type 1), 22 patients with HAE with normal C1 inhibitor, and 91 patients with acquired C1 inhibitor deficiency. Data were provided by 37 centres across the UK. This gives a minimum prevalence of 1:59,000 for HAE-1/2, and 1: 734,000 for acquired C1 inhibitor deficiency in the UK. 45% of patients with HAE were on long-term prophylaxis with the most used medication being danazol (55% of all patients on LTP). 82% of patients with HAE had a home supply of acute treatment with C1 inhibitor or icatibant. 45% of patients had a supply of icatibant and 56% had a supply of C1 inhibitor at home. Conclusions: Data obtained from the survey provides useful information about the demographics and treatment modalities used in HAE and acquired C1 inhibitor deficiency in the UK. These data are useful for planning service provision and improving services for these patients.