Fexofenadine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Fexofenadine is used to treat the symptoms of seasonal allergies (hay fever) in adults and children. Fexofenadine is also used to treat skin itching and hives caused by a condition called chronic idiopathic urticaria in adults and children. Fexofenadine may also be used for purposes not listed in this medication guide.