A curious fact: Photic sneeze reflex. Autosomical dominant compelling helio-ophthalmic outburst syndrome

The sneeze reflex in physiological and pathological states: a mini review

The sneeze reflex serves as a protective response of the human body to environmental stimuli, with its regulatory mechanism largely depending on a complex nervous system. Current research indicates that the sneeze reflex can be triggered by both internal and external stimuli, including light and temperature. The composition of its reflex arc involves the coordinated action of multiple neural structures. Recent in-depth studies on the mechanism of the sneeze reflex have revealed a growing association between this reflex and various diseases, such as allergic rhinitis and infectious diseases. However, existing research primarily focuses on elucidating the neurophysiological basis of the sneeze reflex and its related neural pathways. The manifestations and mechanisms of the sneeze reflex under different pathological states remain underexplored, thereby limiting the potential application of the sneeze reflex in clinical diagnosis and treatment. This review aims to discuss the physiological mechanisms and pathological manifestations associated with the sneeze reflex.

Possible association between photic sneeze syndrome and migraine and psychological distress

Background

Photic sneeze syndrome (PSS) is a condition that causes sneezing when the eye is exposed to sudden bright light. Because alterations in the parasympathetic and trigeminal nerve systems have been implicated in PSS, and such systems are involved in migraine and stress‐related disorders, we examined the possible associations of PSS with migraine and psychological distress.

Methods

The presence of PSS and migraine was examined in 11 840 participants from the general population using a self‐report questionnaire. Psychological distress was assessed by the 6‐item Kessler Psychological Distress Scale (K6).

Results

The overall prevalence of PSS was 3.1%. Individuals with PSS were more likely to suffer from migraine (odds ratio = 1.97, P = 2.18 × 10^–9), clinically relevant psychological distress (K6 score ≥ 5: odds ratio = 1.40, P = 0.00143), and severe psychological distress (K6 score ≥ 13: odds ratio = 1.49, P = 0.0486). Overall, K6 scores were significantly higher in those with PSS than in those without (P = 0.000013). Analysis controlling for sex and the presence of migraine showed that PSS was associated with higher K6 scores irrespective of sex or the presence of migraine.

Conclusions

The low prevalence of PSS identified in the present study may be due to the inadequate ability of the self‐report questionnaire to identify PSS. Despite such limitation, the present study suggests that individuals with PSS are more likely to suffer from migraine and psychological distress than those without PSS. PSS may be a potential target for the research of migraine and stress‐related disorders.

Our data obtained through a self‐report questionnaire administered to 11,840 participants showed that individuals with photic sneeze syndrome were more likely to suffer from migraine and psychological distress than those without photic sneeze syndrome. Photic sneeze syndrome may be a potential target for the research of migraine and stress‐related disorders.

A genome-wide association study on photic sneeze syndrome in a Japanese population

Photic sneeze syndrome (PSS) is characterized by a tendency to sneeze when the eye is exposed to bright light. Recent genome-wide association studies (GWASs) have identified single-nucleotide polymorphisms (SNPs) associated with PSS in Caucasian populations. We performed a GWAS on PSS in Japanese individuals who responded to a web-based survey and provided saliva samples. After quality control, genotype data of 210,086 SNPs in 11,409 individuals were analyzed. The overall prevalence of PSS was 3.2%. Consistent with previous reports, SNPs at 3p12.1 were associated with PSS at genome-wide significance (p < 5.0 × 10^-8). Furthermore, two novel loci at 9q34.2 and 4q35.2 reached suggestive significance (p < 5.0 × 10^-6). Our data also provided evidence supporting the two additional SNPs on 2q22.3 and 9q33.2 reportedly associated with PSS. Our study reproduced previous findings in Caucasian populations and further suggested novel PSS loci in the Japanese population.