In the present study we compared the prevalence of Demodex mites in patients with rheumatoid arthritis and in one control group involving individuals of similar mean age. From each person we epilated 3-4 lashes from each eyelid and examined them under a microscope to find Demodex mites. In total 147 patients were examined. The prevalence of Demodex mites was 33% in rheumatoid arthritis (RA) patients and 31% in the control group. Our results demonstrated that the prevalence of Demodex mites was similar in RA patients as compared to the control group.

Purpose Aim of the study was to estimate the prevalence of Demodex spp. infections of lid margin in Polish population Methods 264 individuals were enrolled in the study. Patients were divided into four groups. First two groups consisted of young people (mean age 22 years) and seniors (mean age 66 years). The third group was made up of people who work with microscopes. Forth group consisted of patients with diagnosed blepharitis. From every individual 3‐4 lashes were epilated from upper and lower lid margin of each eye and examined under the microscope for Demodex mites. Results The lowest number of infected individuals was observed in the young group‐ only 5%, the highest in blepharitis patients‐ 74% infected. Among microscope users (mean age 44 years) 30% were infected, in senior group (mean age 66 years) also 30% were infected. Conclusion Demodex mites are etiological factors of blepharitis. There is a significant correlation between Demodex spp. infection and the age of the examined individual. People who work with microscopes are in a risk group for Demodex infection of lid margins.