Management of hereditary angioedema in resource-constrained settings: A consensus statement from Indian subcontinent

Hereditary angioedema (HAE) is an uncommon disorder characterized clinically by recurrent episodes of nonitchy subcutaneous and/or submucosal swellings. The estimated prevalence of HAE is ~ 1: 10,000 to 1: 50,000. There are no prevalence data from India, however, estimates suggest that there are 27,000 to 135,000 patients with HAE in India at present. The majority of these, however, remain undiagnosed. Replacement of plasma-derived or recombinant C1-esterase inhibitor (C1-INH) protein, administered intravenously, is the treatment of choice during the management of acute episodes of angioedema (i.e., "on-demand treatment") and is also useful for short-term prophylaxis (STP) and long-term prophylaxis (LTP). This has been found to be effective and safe even in young children and during pregnancy. Until recently, none of the first-line treatment options were available for "on-demand treatment," STP or LTP in India. As a result, physicians had to use fresh frozen plasma for both "on-demand treatment" and STP. For LTP, attenuated androgens (danazol or stanozolol) and/or tranexamic acid were commonly used. These drugs have been reported to be useful for LTP but are associated with a significant risk of adverse effects. Intravenous pd-C1-INH, the first-line treatment option, is now available in India. However, because there is no universal health insurance, access to pd-C1-INH is a significant challenge. HAE Society of India has developed these consensus guidelines for India and other resource-constrained settings where plasma-derived C1-INH therapy is the only available first-line treatment option for the management of HAE and diagnostic facilities are limited. These guidelines have been developed because it may not be possible for all patients to access the recommended therapy and at the recommended doses as suggested by the international guidelines. Moreover, it may not be feasible to follow the evaluation algorithm suggested by the international guidelines.