Desloratadine is an antihistamine that reduces the effects of the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Desloratadine is used to treat the symptoms of allergies, such as sneezing, watery eyes, and runny nose. It is also used to treat skin hives and itching in people with chronic skin reactions. Desloratadine may also be used for purposes not listed in this medication guide.