Safety of Astepro 0.15% Nasal Spray and Astepro 0.1% Nasal Spray in Children Ages >6 Months to <6 Years With AR

Approximately 200 subjects, between the ages of ≥ 6 months to \< 6 years of age who have a history of AR will participate in this study. The study will be conducted at about 20 research centers in the United States. Each research center will enroll approximately 2 to 10 subjects. The study will involve at least 4 office visits over at least a 4-week period. You will need to keep the appointments as scheduled by the study personnel. Some medications or therapies could interfere with the safety evaluations conducted in this study. If your child is currently taking any of these medications or therapies, they will need to discontinue them in order to be eligible for this study. Your study doctor will discuss this with you along with information on how this could affect your child's health. If you and the study doctor decide this is appropriate, there is a specific time period that these will need to be discontinued before your child can proceed in study evaluation. If your child is eligible for study participation, he/she will be randomly assigned (by chance, like the flip of a coin) to one of the following two study drug groups: * Astepro (azelastine hydrochloride) 0.15% Nasal Spray, 822 mcg (total daily dose); OR * Astepro (azelastine hydrochloride) 0.1% Nasal Spray, 548 mcg (total daily dose) The following are being performed for the purposes of this study and are not considered standard care: * Your child will be placed in one of the two study drug groups by chance. * You will complete questionnaires about your child's allergy symptoms. * You will complete diary cards each morning recording your child's allergy symptoms over the previous 24 hours. * Your child will have his/her vital signs measured (blood pressure, pulse, temperature and breathing rate). * You and your child will be asked questions regarding your child's use of any medication or supplements and how your child has felt since his/her last visit. * Blood and urine samples will be collected to assess the safety of taking the study drug.