Hereditary angioedema: how to approach it at the emergency department?

Angioedema attacks are common causes of emergency care, and due to the potential for severity, it is important that professionals who work in these services know their causes and management. The mechanisms involved in angioedema without urticaria may be histamine- or bradykinin-mediated. The most common causes of histamine-mediated angioedema are foods, medications, insect sting and idiopathic. When the mediator is bradykinin, the triggers are angiotensin-converting enzyme inhibitors and factors related to acquired angioedema with deficiency of C1-inhibitor or hereditary angioedema, which are less common, but very important because of the possibility of fatal outcome. Hereditary angioedema is a rare disease characterized by attacks of edema that affect the subcutaneous tissue and mucous membranes of various organs, manifesting mainly by angioedema and abdominal pain. This type of angioedema does not respond to the usual treatment with epinephrine, antihistamines and corticosteroids. Thus, if not identified and treated appropriately, these patients have an estimated risk of mortality from laryngeal edema of 25% to 40%. Hereditary angioedema treatment has changed dramatically in recent years with the development of new and efficient drugs for attack management: plasma-derived C1 inhibitor, recombinant human C1-inhibitor, bradykinin B2 receptor antagonist (icatibant), and the kallikrein inhibitor (ecallantide). In Brazil, plasma-derived Cl inhibitor and icatibant have already been approved for use. Proper management of these patients in the emergency department avoids unnecessary surgery and, especially, fatal outcomes.