Correlation Demodex Folliculorum and Skin Biophysical Parameters

摘要

Purpose: Demodex folliculorum is a transparent mite, 0.3 - 0.4 mm long, which asymptomatically parasitizes the human pilosebaceous follicles. D. folliculorum is observed in normal skin with a prevalence of 100% and a density of ≤ 5 D/cm2 in the adult population. Materials and Methods: This study evaluated the differences in pH on the five facial sites between the two populations with and without D. folliculorum. The relationship between pH and skin surface oil was analyzed in populations with and without Demodex mites. Mongolian 750 subjects (370 males and 380 females) aged 16 - 84 years, who lived in Ulaanbaatar city, were enrolled in this study. The eligibility criteria included a minimum age of 16 and no physical and dermatologic illness, no cosmetic. Results: Skin surface oil among the five facial areas differed significantly in both subjects with and without Demodex folliculorum (P < 0.001). When the skin surface oil on the T-zone, U-zone was compared, those on the T-zone were significantly higher than those of the U-zone (P < 0.001) in both populations (P< 0.01). The pH levels on the five facial sites, and U-zone, T-zone and MFpH differed significantly in among both subjects with and without Demodex folliculorum (P < 0.001). In both groups, the pH levels of the U-zone were significantly lower than the pH of the T-zone (P Conclusions: Among the five facial sites in subjects with Demodex folliculorum, there were significant negative correlations between skin surface oil and pH on the forehead (p < 0.001, r = 652), cheek (P < 0.001, r = 0.656), nose (P < 0.001, r = 0.754), chin (P < 0.001, r = 0.679), and T-zone (P < 0.001, r = 0.698), MFSE-MFpH (P < 0.001, r = 0.483). In contrast, among the five sites in subjects without Demodex folliculorum, a significant negative correlation between skin surface oil and pH was observed on the forehead (p < 0.001, r = 766), cheek (P < 0.001, r = 0.798), nose (P < 0.001, r = 0.706), chin (P < 0.001, r = 0.823), and T-zone (P < 0.001, r = 0.602), U-zone (P < 0.001, r = -0.550)