Poor sleep and daytime somnolence in allergic rhinitis: Significance of nasal congestion

Patients with allergic rhinitis frequently present with symptoms of nasal congestion, runny nose, sneezing, daytime somnolence and fatigue associated with decreased cognitive performance and impaired quality of life. Recent research has suggested that daytime somnolence in allergic rhinitis can be attributed to chronic inflammation of the nasal mucosa leading to nasal congestion and obstructed nasal passageways resulting in disturbed sleep. Treating daytime somnolence due to allergic rhinitis requires a reduction in obstruction caused by nasal congestion. Currently available therapy for allergic rhinitis includes topical corticosteroids, sedating and nonsedating antihistamines, topical cromolyn sodium (sodium cromoglycate), decongestants, immunotherapy and topical ipratropium bromide. The effectiveness of antihistamines in patients with allergic rhinitis has long been established. However, results of placebo-controlled trials investigating the effects of azelastine on sleep and daytime somnolence have produced conflicting results. Sleep improved with azelastine therapy, but there was a lack of evidence that azelastine significantly affected daytime sleepiness, sleep severity and nasal congestion. Sedating antihistamines exacerbate daytime somnolence and should be avoided in patients with allergic rhinitis. In a separate study, desloratadine failed to benefit sleep, but did not worsen daytime somnolence. Topical nasal cromolyn sodium is inconvenient to use and is unlikely to have a major effect on nasal congestion. Decongestants do decrease nasal congestion but the effect this has on sleep has not been adequately studied. Recent research has shown that topical corticosteroids are an effective treatment for alleviating nasal congestion secondary to allergic rhinitis. However, few studies have assessed the effect of topical corticosteroids on daytime fatigue and sleep. In 20 patients with allergic rhinitis and symptoms of daytime sleepiness, flunisolide significantly improved sleep quality and congestion but daytime sleepiness was not significantly improved. A similar study with fluticasone propionate showed improvement in nasal congestion and sleep but there was no significant change in objective sleep measurements recorded on polysomnography. Further research involving objective measures of sleep quality is necessary to determine the efficacy of medications in the treatment of allergic rhinitis associated with fatigue and daytime somnolence.