Rhinitis therapy and the prevention of hospital care for asthma: a case-control study.

Background: Although clinical trials have demonstrated that rhinitis therapy improves subjective and objective measures of asthma, it is uncertain whether treatment of allergic rhinitis significantly affects the frequency of asthma exacerbations.

Objective: The objective of this study was to determine whether treatment with intranasal corticosteroids and/or second-generation antihistamines is associated with changes in rates of asthma exacerbations resulting in emergency room visits and/or hospitalizations in patients with asthma and allergic rhinitis.

Methods: This was a nested, case-control study.