Demodex parasite density in patients with melasma: a case-control study

Background Although multiple factors contribute to the development of melasma, there are reports suggesting a potential role of Demodex parasites in hyperpigmentation. This study aimed to compare the density and prevalence of Demodex infestation between patients with melasma and healthy controls.Methods This case-control study included 35 melasma patients and 35 healthy volunteers. Standard superficial skin biopsies using cyanoacrylate adhesive were taken from the malar regions. Samples were examined via light microscopy, with a density of ≥5 Demodex/cm2 defined as positive.Results No statistically significant difference was found between the melasma and control groups in terms of Demodex mite density or positivity rates. Correlation analysis revealed no significant relationship between mMASI scores and Demodex mite density. As a secondary finding, the mean mMASI score was significantly higher in male participants compared to female participants.Conclusion In this case-control study, we found no statistically significant association between Demodex parasite density and melasma in our study population. While our findings do not support an association in this sample, future large-scale and multicenter studies could further explore the potential role of Demodex in skin disorders that have been suggested by other reports. The single-center design and moderate sample size should be considered when interpreting these results.