Wilken JA, Berkowitz R, Kane R. Ann Allergy Asthma Immunol. 2002;89:372–380
Purpose of the Study.
Previous studies have shown adverse effects on sedation, cognition, and psychomotor performance in patients with allergic rhinitis with or without medical therapy. This study was done to further delineate the impact and consequences of symptomatic allergic rhinitis on vigilance and a wide range of tests of cognitive function.
Two hundred ninety-six adults (mean age: 36–37 years) were studied in an allergen exposure unit (AEU). The subjects had a minimum 2-year history of ragweed-associated allergic rhinitis with positive prick/puncture or intradermal skin tests to ragweed. The patients were not allowed to be on any other medications for allergy, asthma or central nervous system (CNS) depressants or stimulants.
This was a randomized, parallel-group, single-center study. The patients were all asymptomatic during an initial screening period and for baseline testing. The patients were administered a battery of automated neuropsychologic tests at baseline. The primary measure was the Kay Continuous Performance Test (KCPT), which is a measure of vigilance or the ability to maintain a certain level of arousal or attention while engaged in a monotonous or repetitive task. Secondary tests measured working memory, psychomotor speed, reasoning/computation, and divided attention. After the asymptomatic screening period and baseline testing, subjects were divided into symptomatic or asymptomatic groups. The symptomatic group was exposed to a consistent pollen level in the AEU. The symptomatic subjects could have as many as six 90-minute allergen exposure sessions over a 7-day period until they achieved specified levels of symptoms. Then, the testing was repeated as well as repeated in an asymptomatic control group with allergic rhinitis who had no pollen exposure in the AEU.
Symptomatic allergic rhinitis had major adverse impacts on measures of vigilance. Symptomatic subjects performed significantly worse than asymptomatic subjects on all parameters of the KCPT. The cognitive battery of tests also showed a negative impact on a broad range of cognitive functions in symptomatic allergic rhinitis subjects. The greatest effect sizes were for tests measuring working memory and psychomotor speed.
Symptomatic, untreated allergic rhinitis subjects were found to have a significant decrement on measures of vigilance and a broad range of cognitive functions.
Another study showing cognitive changes in patients with allergic rhinitis. Another reason not to compound the problem with first-generation, sedating antihistamines.