Urticaria and angioedema.

Urticaria and angioedema evoke a completely different differential diagnosis from angioedema without an associated urticarial syndrome. This review of the literature is to give the reader a global insight into the spectrum of urticaria and angioedema, focusing on differential diagnosis and pathogenic mechanisms. It will define the role of the mast cell, explore a possible autoimmune basis for urticaria, and examine the purported role of food allergy in chronic urticaria. Last, the work-up and treatment will be discussed. Urticaria and angioedema are frustrating problems for both physicians and their patients; however, the problem can best be approached by considering urticaria as a symptom rather than a specific disease. The physical examination and medical history remain the two most important pieces of information.