Increased incidence of chalazion associated with face mask wear during the COVID-19 pandemic



To determine whether the incidence of chalazion increased significantly in the San Francisco Bay Area and Los Angeles County following the widespread adoption of face mask wear in response to the COVID-19 pandemic.


This is a retrospective multicenter study of two ophthalmology institutions: a private Oculoplastics practice in San Francisco and the Oculoplastics division of the Stein Eye Institute at the University of California, Los Angeles. All patients seen during the studied time periods with a diagnosis of chalazion or hordeolum were identified through review of electronic medical records and included in the study. Incidence was determined for each month between January and August 2020, and compared to data from prior years via ANOVA to evaluate for changes after the onset of the pandemic.


In San Francisco, the incidence of chalazion rose significantly in June through August of 2020 when compared to the same interval in 2016, 2017, 2018, and 2019. In Los Angeles, the rise in chalazion incidence in 2020 was also statistically significant when compared to data from the years 2018 and 2019.


Importance: Widespread mask wear does appear to correspond to an increased incidence of chalazion. This risk may be minimized, while still maintaining the protective benefits of mask wear, by taking the proactive measures discussed to decrease mask induced eye dryness and changes in the eyelid microbiome.


Since the novel 2019 coronavirus disease (COVID-19) was declared a pandemic by the World Health Organization (WHO) in March 2020, efforts to minimize its spread have included preventive measures such as social distancing, hand hygiene and face mask wear. , In the United States, the use of facial coverings made from paper or cloth rose dramatically during the pandemic, driven by recommendations released by the Centers for Disease Control and Prevention (CDC) in April 2020. The increased use of face masks has been linked to unintended consequences in the general population, including an increased incidence of acne driven by localized increases in temperature and humidity. Since wearing a non-respirator face mask generally directs breath upwards to the periorbital area ( Fig. 3 ), it has been hypothesized that wearing such masks may also create a suitable micro-environment for eyelid inflammation and contribute to the development of chalazion.

The aim of this study was to determine whether the incidence of chalazion rose following the widespread implementation of paper or cloth face coverings in response to the COVID-19 pandemic. Through retrospective analysis of medical records from two geographically disparate Oculoplastic practices in California, we explored the incidence of chalazion before and after the CDC’s recommendation for face coverings, comparing rates during these time periods to those from prior years to determine whether there is a correlation between widespread mask wear and chalazion incidence.

Materials and methods

In this retrospective study, the medical records from two California Oculoplastic practices: a private practice (Silkiss Eye Surgery, San Francisco, USA) and a tertiary referral academic center (Stein Eye, University of California, Los Angeles, USA), separated geographically by 400 miles were reviewed. In the private practice, medical records between the months of January and August, for the years 2016–2020, were analyzed for the incidence of chalazion (CPT and ICD10 codes 67800, 67801, H00.1) per all patient visits. The same methods were used to analyze data from the academic center from 2018 to 2020, where the incidence of chalazion was calculated among all visits for ocular symptoms. All statistical analyses were performed with SPSS version 22.0 (SPSS, Inc., Chicago, Illinois, USA). Analysis of variance (ANOVA) was used to determine whether the differences in chalazion incidence at different time points were statistically significant.

The research adhered to the tenets of the Declaration of Helsinki as amended in 2008 as the Health Insurance Portability and Accountability Act (HIPAA) of 1996. It was not appropriate or possible to involve patients in the design, or conduct, or reporting, or dissemination plans of our research.


At both institutions, the incidence of chalazion rose significantly in 2020 as compared to prior years. In the San Francisco (SF) private practice, partially closed due to local lockdown measures in April and May, between June and August of 2020, 202 of 1338 patients were seen for chalazion, reflecting an incidence of 0.151. For comparison, during the same time interval in 2019, 124 of 1631 (incidence 0.076) patients were seen for chalazion ( Table 1 and Fig. 1 ).

Table 1

The incidence of chalazion per month in San Francisco between 2016 and 2020. Note April and May are excluded due to practice shutdown during state-mandated stay-at-home orders.

Jan Feb Mar Jun Jul Aug
2016 0.0418 0.0746 0.0875 0.0653 0.0603 0.0417
2017 0.134 0.0459 0.0545 0.0505 0.0339 0.0824
2018 0.0791 0.0916 0.0948 0.0705 0.097 0.0769
2019 0.0512 0.0532 0.0669 0.0821 0.0752 0.0752
2020 0.112 0.0936 0.0912 0.173 0.131 0.131

Fig. 1

Chalazion Incidence at San Francisco Private Practice and New Cases of COVID-19 in San Francisco County.

The incidence of chalazion in San Francisco per month between 2016 and 2020, overlaid by incidence of new cases of COVID-19 throughout studied months. Note April and May are excluded due to practice shutdown during state-mandated stay-at-home orders.

At the Los Angeles (LA) academic center, which did not undergo the same lockdown mandated closures, chalazion incidence began to rise steeply after the pandemic declaration ( Fig. 2 ). Between March and May of 2020, 939 patients were seen for chalazion, reflecting an incidence of 0.044. During the same time interval in 2019, the incidence was 0.027. Between June and August 2020, 1165 patients were seen for chalazion (incidence 0.031). In this interval, numbers from 2019 were similar, with 1165 chalazion patients seen and an incidence of 0.028 ( Table 2 ). The difference in incidence of chalazion between January and September 2018, 2019, and 2020, revealed that the increase in 2020 was significant (f-ratio = 5.27 and p < 0.01).

Jul 10, 2021 | Posted by in OPHTHALMOLOGY | Comments Off on Increased incidence of chalazion associated with face mask wear during the COVID-19 pandemic
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