ABSTRACT
Background: Little is known about how many patients with hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) receive on-demand and/or prophylactic treatment and what their clinical features are. Here, we estimated, using Delphi-based consensus, prevalence and treatment patterns in Germany as well as patient features linked to long-term prophylaxis. Materials & Methods: Eight experts, who together treat approximately 75% of all German HAE-C1-INH patients, participated in a classic, two-round Delphi survey. Consensus was defined as agreement between at least 75% of participants. Results: Experts agreed that an estimated 1,350 patients in Germany have HAE-C1-INH, i.e. 1.62 per 100,000. One in four patients was estimated to receive long-term prophylaxis. Patient features linked to the use of prophylactic treatment included reduced quality of life, frequent swellings and swellings that affect the upper airways, and >two attacks per month. Conclusion: The rate of prophylactic treatment in Germany is low, but is expected to increase. The level of disease activity and its impact and control are and should be considered in the choice for prophylactic treatment.