Pilot-study of photodamaged skin and melasma using reflectance confocal microscopy

Abstract

Introduction: Photoaging and melasma are frequent dermatological complaints. Confocal reflectance microscopy (CRM) is a recent technique that can be used for diagnostic evaluation of these dermatoses. Objectives: To evaluate the characteristics of the epidermis and dermis containing pigmentary alterations caused by photodamage and melasma with the assistance of CRM, and compare the findings linked to these changes with the perilesional region. Methods: A pilot study was conducted with eight female individuals (aged 38 to 50 years, Fitzpatrick phototypes from II to IV) with clinical diagnoses of photodamage (n = 4) and melasma (n = 4) in the facial malar region. The perilesional and lesional regions were compared regarding the thickness of the stratum corneum and viable epidermis, the depth of the interpapillary crests, and the presence of hyper-refractive structures. Results: The pigmentary alterations in the photodamaged skin revealed a morphological pattern — such as an increase in the depth of the interpapillary ridges in the lesion region — typical of solar lentigo. In the lesional region of volunteers bearing melasma, it was possible to observe the presence of dendritic cells in the epidermis and melanophages in the dermis. All volunteers had hyper-refractive keratinocytes in the lesional epidermis region. Conclusions: Considering the number of patients evaluated, it was possible to characterize and compare cutaneous pigmentary alterations caused by photodamage to those cause by melasma.