Effect of Phototherapy on Demodex Parasite Density

Background: Demodex parasites are the most common ectoparasites in humans. One of the factors in the pathogenesis of an increase in parasite density is immunosuppression. In this prospective study, we aimed to evaluate the effect of phototherapy-induced immunosuppression on Demodex density. Material and Methods: Thirty-five patients receiving phototherapy were included in the study. The number of parasites in the samples taken from the right cheek, left cheek, forehead, nose and chin of the patients, by standardized skin surface biopsy method, were recorded before phototherapy and in the third month of treatment. Results: Of the 35 patients, the female-to-male ratio was found to be 2.1:1. There was no statistically significant difference between the ages of the male and female patients. The increase in the number of parasites in the right cheek, left cheek, nose and chin in the third month was statistically significant; whereas the increase in the forehead was not. Conclusion: The results of our study showed that phototherapy can cause an increase in Demodex density, and these findings are compatible with those of other studies in the literature. Since our study aims to evaluate density at the beginning and the end of the third month of phototherapy, it differs from other studies by indicating the effect of phototherapy more accurately.