Allergic rhinitis is a risk factor for traffic safety

Allergic rhinitis (AR) affects up to 30% of the adult population and symptomatic patients continue to engage in daily life activities, including car driving. Previous studies have shown that AR can impair cognitive functions, especially during longer-lasting tasks. Other reports suggest negative effects on psychomotor functions such as driving, but no clear evidence has been presented yet.

Primary objective was to determine the effect of AR per se on actual driving performance and compare it with the effects of treated AR.

Nineteen patients with documented AR history underwent a unique and validated 1-h on-the-road driving test outside the pollen season. In a 4-leg repeated measures design, patients underwent a nasal provocation test with either pollen or inactive control prior to the driving test. In the three conditions with pollen provocation, patients were pretreated with either cetirizine 10 mg, fluticasone furoate 27.5 μg, or placebo to alleviate the provoked AR symptoms.

The driving performance of patients when symptomatic and not treated was significantly impaired compared to the placebo condition. When engaging in a secondary memory task during driving, their performance deteriorated further. The magnitude of impairment was relevant and comparable to that seen at a blood alcohol level of 0.05%, the legal limit in many countries. Treatment of AR symptoms partially counteracted the effect of AR on driving.

Untreated AR can impair driving ability and put patients at risk. Drug therapy reduces this impairment, and AR patients should therefore be advised to always treat their condition.