Abstract
INTRODUCTION: The present study aimed to obtain fundamental data, including climate conditions and Demodex mites, on rosacea and similar diseases in the situation where the wearing of face masks is mandatory due to the coronavirus disease 2019 pandemic. METHODS: We enrolled 86 Japanese patients habitually wearing face masks with rosacea and similar diseases. Disease severity was assessed using the Investigator Global Assessment. The presence of Demodex mites was examined microscopically. Treatment involved acaricidal and antibiotic agents. RESULTS: The numbers of male and female patients enrolled were 11 and 75, respectively. Among these patients, 85 (98.8%), 57 (66.3%), and 76 (88.4%) had rosacea, rosacea-like dermatitis (RLD), and demodicosis, respectively. The monthly number of patients with rosacea and demodicosis showed two peaks from May to June and in October, during which monthly mean temperature was approximately 20°C (68°F). Improvement rates in rosacea, RLD, and demodicosis were significantly higher when Demodex mites were no longer detected after treatment. CONCLUSION: The present results suggest that a season with a mean temperature of approximately 20°C is a risk factor for rosacea and similar diseases in individuals wearing face masks in Japan, and a decrease in Demodex mites is associated with the attenuation of symptoms.