Evaluation of demodicosis, nailfold capillaroscopy, and oxidative stress in rosacea: a case-control study

Introduction: Inflammation, immune system disorders, Demodex infestation, neurovascular dysregulation and oxidative stress are thought to be contributory factors in the pathogenesis of rosacea. Aim: To evaluate the presence of Demodex mites, the morphologic features of the nailfold capillaries, and the systemic oxidative stress status in patients with rosacea. Material and methods: Thirty-one patients diagnosed with rosacea and 37 healthy age- and gender-matched subjects were included in this prospective case-control study. The presence of Demodex infestation, the findings of nailfold capillaroscopy (NFC), and the status of systemic oxidative stress measured by total oxidant capacity (TOC), total antioxidant capacity (TAC) and oxidative stress index (OSI) were evaluated. Results: Demodex infestation rates were significantly higher in rosacea patients than in controls (p = 0.001). Increases in the diameters of the capillaries and the presence of avascular areas and crossing and abnormal structures were significantly more common in rosacea patients than in the healthy controls (p < 0.01, p = 0.016, p = 0.02, p < 0.001, respectively), and hairpin structures were significantly less common in rosacea patients than in the controls (p < 0.001). The presence of crossing capillaries was positively correlated with higher TOC levels (p = 0.05), while abnormal structures were found to be correlated with lower levels of TAC (p = 0.045). Conclusions: Oxidative status and NFC may play diagnostic and prognostic roles in rosacea, which should be confirmed by studies with larger sample sizes.