Reflectance confocal microscopy for monitoring the density of Demodex mites in patients with rosacea before and after treatment

Summary Background Demodex mites seem to serve as a pathogenic trigger in many Demodex‐associated diseases such as rosacea. In facial skin of patients with rosacea significantly higher numbers of Demodex mites have been shown compared with healthy controls. Reflectance confocal microscopy (RCM) allows the detection and quantification of Demodex mites in vivo noninvasively. It is hypothesized that a reduction of Demodex mites under rosacea therapy can be monitored by RCM. Objectives To use RCM to monitor the density of Demodex mites in patients with rosacea before and after treatment. Methods In 25 patients with facial rosacea RCM was performed before and after therapy. Mosaics of 5 × 5 mm2 and 8 × 8 mm2 were scanned, and the total numbers of mites per follicle and per area were counted, along with the number of follicles per area. Results In all patients Demodex folliculorum could be detected and quantified using RCM. RCM showed significant differences pre‐ and post‐treatment (P = 0·0053 for 5 × 5 mm2 and P