Value of reflectance confocal microscopy for the monitoring of rosacea during treatment with topical ivermectin.

Background: Reflectance confocal microscopy (RCM) enables noninvasive Demodex mite detection in rosacea. Objective scoring of rosacea severity is currently lacking.Objectives: To determine the value of RCM for monitoring Demodex, inflammation and vascular parameters in rosacea during treatment.Methods: In 20 rosacea patients, clinical and RCM examination were performed before, during, and 12 weeks after a 16-week treatment course with topical ivermectin. Using RCM, number of mites and inflammatory cells, epidermal thickness, and vascular density and diameter were measured. RCM features were correlated with clinical assessment.Results: Treatment resulted in clinical reduction of inflammatory lesions. Mites were detected in 80% of patients at baseline, 30% at week 16, and 63% at week 28. The number of mites reduced significantly during treatment, but no changes in inflammatory cells, epidermal thickness or vascular parameters were observed. Correlation between number of inflammatory lesions and mites was low. None of the RCM variables were significant predictors for clinical success.Conclusions: RCM enables anti-inflammatory effect monitoring of topical ivermectin by determining mite presence. Quantifying exact mite number, and inflammatory and vascular characteristics is challenging due to device limitations. In its current form, RCM seems of limited value for noninvasive follow-up of rosacea in clinical practice.