Differential diagnosis of angioedema.

Angioedema without an associated urticarial syndrome evokes a completely different differential diagnosis from urticaria. This review of the literature discusses hereditary angioedema as prototype of angioedema without urticaria. The review then establishes a differential diagnosis for angioedema, which includes allergic contact dermatitis, connective tissue disease, endocrine associations, parasitic disease, tumor masses, and miscellaneous causes for angioedema. Angioedema without urticaria is a distinct syndrome differing from chronic urticaria. The astute clinician should be familiar with the spectrum of disorders ranging from a functional or quantitative deficiency in C1-esterase inhibitor to a panoply of cutaneous and internal medical disorders. Angioedema without urticaria is a symptom in which there are many different disease mechanisms producing subcutaneous swelling recognizable as angioedema.