OBJECTIVE: To characterize the treatment and costs associated to rhinitis in a managed care population. METHODS: All subjects contained within PharMetric’s Integrated Outcomes database possessing a diagnosis of rhinitis (ICD-9-CM = 477) and a prescription claim for a rhinitis specific medication during 1997-1998 were eligible for study inclusion. Patients were required to have 12 months of data following the first (index) rhinitis diagnosis present. Patients were stratified according to the number of comorbid conditions (0 comorbidities, 1 comorbidity, > 1 comorbidity). Measured conditions included upper respiratory infections, sinusitis, asthma, bronchitis, conjunctivitis, and otitis media. Patient demographics, rhinitis specific charges, and comorbid conditions were captured for each patient during the study period. RESULTS: 202,426 patients met the inclusion criteria. The mean age was 33.9 years (SD=17.7) and 61.4% were female. The most commonly identified comorbid conditions were upper respiratory infection (32.2%) and sinusitis (34.2%). The proportion of females increased with the presence of comorbid conditions, as did prescription therapy. The most common antihistamine was loratadine, which was prescribed to approximately 57% followed by fexofenadine (19%) and cetirizine (14%). Nasal steroids were prescribed to over half of the sample (58%). Mean rhinitis specific treatment charges for the 12 months following initial diagnosis range from $371 (SD=365) to $590 (SD=642) for patients with 2 or more comorbidities. CONCLUSION: Rhinitis is a prevalent condition within this managed care population, associated with substantial utilization of healthcare resources.