Learning impairment and allergic rhinitis.

Allergic rhinitis is underestimated as a cause of suffering and diminished quality of life in children and adolescents. If nasal symptoms such as itching, sneezing, rhinorrhea, and congestion are not well controlled during the day, they may contribute to learning problems during school hours. If these symptoms are not well controlled during the night, they may contribute to nocturnal sleep loss, secondary daytime fatigue and learning impairment. Even uncomplicated seasonal allergic rhinitis may be associated with reduced ability to learn, and the likelihood of learning problems may increase in severe perennial rhinitis or in rhinitis associated with complications such as sinusitis or eustachian tube dysfunction and conductive hearing loss. Also, many of the medications used to treat allergic rhinitis may cause central nervous system adverse effects and contribute to learning impairment. For some medications, such as inhaled glucocorticoids and decongestants, the potential effect on central nervous system function and learning has not been tested. For others such as H1-receptor antagonists (antihistamines), well-designed, prospective studies have been performed. The newer relatively nonsedating medications such as terfenadine, astemizole, loratadine, cetirizine, and fexofenadine have less potential to impair central nervous system function and learning than their predecessors.