Introduction: Photokeratoconjunctivitis (PKC) is primarily caused by welding. However, inappropriate use of germicidal lamps, which have been widely used following the COVID-19 outbreak, can also cause PKC. Our goal in this study was to investigate the incidence of and changes in the causes of PKC during the coronavirus 2019 (COVID-19) pandemic.

Methods: We conducted a single-center, retrospective observational study. The health records of patients who visited the emergency department in a tertiary care hospital from January 1, 2018–December 31, 2021 and were diagnosed with PKC, were reviewed. We then conducted an analysis to compare the characteristics of PKC before and after COVID-19 began and the features of PKC caused by welding and germicidal lamps.

Results: There were 160 PKC cases with a clear etiology before the COVID-19 pandemic and 147 cases during the COVID-19 pandemic. No significant differences in age and gender were detected between the two groups. The incidence of PKC induced by the use of germicidal lamps during the COVID-19 pandemic was significantly higher (10.2%) than the incidence before the pandemic (3.1%). The ratio of females to males in the germicidal lamp subgroup was significantly higher than the ratio in the welding subgroup. Limitations included incomplete information due to the retrospective nature of the study, underestimation of incidence, and possible recall bias.

Conclusion: In the era of COVID-19, clinicians should be aware of the hazards of germicidal lamps. Although the COVID-19 pandemic seems to show signs of easing, new infectious diseases that require protective measures could still emerge in the future. Therefore, injuries related to germicidal lamps deserve more public health attention.