Drug-induced angioedema.

Angioedema (AE) is the end result of deep dermal, subcutaneous and/or submucosal swelling, and represents a major criterion in the definition of anaphylaxis. Drug-induced AE, like other cutaneous drug reactions, is most frequently elicited by betalactam antibiotics and nonsteroidal antiinflammatory drugs. However, differences exist in their underlying pathophysiology (IgE mediated vs. pseudoallergic). Blockers of the renin-angiotensin-aldosterone system are the most common class of medications associated with isolated AE and are most probably related to elevated bradykinin levels. Typically, ACE inhibitor-associated AE can occur up to several years after initiating treatment, and may sporadically recur even after discontinuation. A comprehensive investigation of AE must include analysis of complement factors, tryptase levels as well as specific allergy tests. Furthermore, other possible causative agents ought to be excluded. Every patient with drug-induced AE must receive an allergy pass as well as emergency medication including epinephrine. In some cases, inhibitors of the bradykinin system may be considered for treatment.