Xyzal (Levocetirizine) 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. Xyzal is used to treat symptoms of year-round (perennial) allergies in adults and children who are at least 6 months old. Xyzal is also used to treat itching and swelling caused by chronic urticaria in adults and children who are at least 6 months old.