The effect of skin moisture, pH, and temperature on the density of Demodex folliculorum and Demodex brevis (Acari: Demodicidae) in students and staff of the Erzincan University, Turkey

Background: The aim of this study was to determine the prevalence and density of Demodex folliculorum and Demodex brevis in students and staff of the Erzincan University, Turkey, and to define the influence of age, gender, educational level, and hygiene as well as skin moisture, pH, and temperature on the presence of Demodex mites. Methods: Healthy people without apparent facial dermatoses from nine faculties and five vocational schools of the university were included in the study. The measurements for moisture, pH, and temperature were conducted in the cheek region, while samples for mite presence were taken from the same region using the standard superficial skin biopsy technique. Results: A total of 538 healthy people, 385 students and 153 university staff, were included in the study. Demodex mites were detected in 50.1% of the students (mean 7.1/cm2) and in 69.3% of the university staff (mean 13.1/cm2). There were statistical differences between the groups of people who were cleaning their face one, two, three, or more times daily and between those who were using and not using personal towels. There was a borderline significant difference between the different age groups and people with different education levels. The density of mites was higher in those with a skin moisture of less than 50%, with a pH of 5–6.5 and temperature of 24–28 °C, however the differences between the groups with different skin moisture, skin pH, and skin temperature were not statistically significant. Conclusion: Demodex mites are very prevalent in healthy individuals of both sexes, and this should be taken into consideration when epidemiological and clinical studies are conducted with patients having different dermatological ailments. © 2017 The International Society of Dermatology