The effect of treatment of allergic rhinitis on asthma morbidity, including emergency department visits

Purpose of review It has been hypothesized that asthma and allergic rhinitis are both manifestations of a single inflammatory process present throughout the airway and that control of the inflammatory response associated with allergic rhinitis may help to reduce inflammation throughout the airway and improve control of asthma. Although previous evidence has documented that therapy directed at allergic rhinitis can improve asthma symptoms and bronchial responsiveness, until recently, there was no evidence that the use of medication targeted at the upper airway can also reduce utilization of acute health care services due to asthma. Recent findings We identified studies published between August 2001 and July 2002 that examined the therapeutic link between allergic rhinitis and asthma. In particular, we concentrated on investigations that evaluated whether, among patients diagnosed with allergic rhinitis and asthma, treatment of the former resulted in significantly fewer asthma-related emergency department visits or inpatient hospitalizations. Two such studies were identified. Using observational study designs, both investigations established that among a population with asthma and allergic rhinitis, treatment for allergic rhinitis was associated with a decrease in the risk of subsequent asthma-related events by one-third to one-half compared with persons who did not receive treatment for this disorder. Summary Effective management of allergic rhinitis with nasal steroids and possibly oral antihistamines reduces utilization of acute health care services due to asthma among persons with co-existent asthma.