Angioedema (BE: angiooedema), also known by its eponym Quincke's edema and the older term angioneurotic edema, is the rapid swelling (edema) of the skin, mucosa and submucosal tissues. If it proceeds rapidly, it can lead to airway obstruction and suffocation, and it should therefore be treated as a medical emergency.

An antihistamine is a drug which serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions, through action at the histamine receptor. Only agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines - other agents may have antihistaminergic action but are not true antihistamines.

Angioedema as related to Antihistamines