KNG1 and angioedema: Angioedema can be defined as either hereditary (bradykinin) or acquired (bradykinin or histamine) (Table 1).1–5,7,15,19–24 The underlying pathophysiology (ie, bradykinin-vs histamine-mediated) influences the clinical presentation and treatment recommendations.1,2,7,8 Bradykinin-mediated forms are generally more severe, longer lasting, and frequently involve the upper airway and gastrointestinal (GI) system.1,20–24