Investigations on the prevalence of the photo-induced sneezing reflex in the German population, a representative cross-sectional study.

The sneezing reflex is a common phenomenon in human beings and animals. Until now largely uninvestigated sneezing phenomenon is the photic sneeze reflex, also known as the ACHOO (Autosomal Cholinergic Helio-Ophtalmologic Outburst). This light induced sneezing reflex is triggered by a bright light like the sun but also by artificial light. In former publications the prevalence of this phenomenon in the population is specified up to 35 % and can result in a potential endangerment in numerous everyday situations as driving a car or controlling an airplane. In our present study we interviewed 1042 patients in the Department of Otorhinolaryngology of the Saarland University Hospital using standardized questionnaires to analyse epidemiological data as age, gender and known diseases. Additionally, the questionnaire focused on the occurrence of sneezing events, extend of sneezing, potential triggers, and methods of evasion. In our data analysis, we were able to show a high prevalence of the ACHOO in 57 % of our cohort, suffering from regular light induced sneezing events. Excluding subjects reporting only occasional sneezing events our results were comparable to findings in literature. As expected a familial disposition was observed, additionally tobacco smoking correlated with light induced sneezing events. Analyzing a large cohort, we were able to demonstrate that the prevalence of the ACHOO in the german population may be higher than expected. Taken into account the potential hazard caused by this phenomenon, further investigations should identify the pathophysiologic pathway.