Reflectance confocal microscopy vs. standardized skin surface biopsy for measuring the density of Demodex mites

Reflectance confocal microscopy (RCM) has been recently shown to be effective for measuring the Demodex mite density.

To compare and demonstrate the advantages and disadvantages of standardized skin surface biopsy (SSSB) and RCM for measuring the density of Demodex mites.

Forty-eight patients (30 female, 18 male) and 47 healthy controls (30 female, 17 male) were enrolled in the study. The patients diagnoses were pityriasis folliculorum (n = 40), papulopustulary rosecea (n = 7) and erythema-telengiectatic rosacea (n = 1). The area with the most intense erythema on the right cheek was selected for imaging with RCM (VivaScope 3000) and SSSB.

Forty-two patients demonstrated high Demodex density [(Dd) > 5 mites/cm(2) ] with SSSB (85.7%). RCM identified demodicosis in 48 patients (100%). The mean Dd measured with RCM (409.8 ± 209.2) was significantly higher than SSSB (15.33 ± 18.1) (P < 0.001). In the patients, RCM demonstrated the mean number of mites 40.90 ± 20.9 and 4.11 ± 6.4 in the controls per 10 mm(2) area. The corresponding mean number of 2.63 ± 0.77 mites was detected in the infested follicles per area of view compared to a mean of 0.77 ± 0.98 mites in the infested follicles in the controls (P < 0.001).

Reflectance confocal microscopy is a fast, direct and noninvasive method for Demodex-associated diseases and it is superior to SSSB for Demodex mite detection.