Second‐ and third‐generation antihistamines in the treatment of urticaria

ABSTRACT: Chronic urticaria is mainly idiopathic in nature and can be difficult to treat. While less responsive to antihistamine therapy than acute urticaria, antihistamines still play a key role in the management of symptomatology. While many of the antihistamines still commonly used to treat urticaria are first generation H1 antagonists (e.g., diphenhydramine, hydroxyzine), the more recently developed second-generation agents (e.g., loratadine, cetirizine) and their metabolites—the third-generation antihistamines (e.g., fexofenadine, norastemizole, descarboxyloratadine)—possess many of the desirable clinical effects of the first-generation agents with a more tolerable side effect profile. This review discusses the advantages and disadvantages of each of the various second- and third-generation agents available, and presents some of the data showing the differences among these agents in the treatment of chronic urticaria.