Real-World Evidence on the Management of Hereditary Angioedema With Normal C1 Inhibitor.

Summary: Hereditary angioedema (HAE) is a rare disease that causes severe swelling, often in the belly. This study looked at 116 patients in Brazil who have a specific type of HAE where a certain blood protein is normal. Almost all of these patients were women. Doctors found that the best way to treat the most common form of this disease is to stop taking birth control pills that contain estrogen. This simple step worked very well and worked even better when patients took a different hormone called progestin instead. Stopping estrogen greatly reduced the number of swelling attacks. Other medicines, like tranexamic acid or lanadelumab, helped some patients too. Because symptoms can come back years later due to hormone changes, patients need to be checked regularly by their doctors.