Anin vivomodel for postinflammatory hyperpigmentation: an analysis of histological, spectroscopic, colorimetric and clinical traits

Abstract

Clinical, spectroscopic and histological similarities of acne-induced and TCA-induced PIH at day 28 suggest that TCA-induced PIH can be a reproducible model for the study of acne-induced PIH.

Synergistic effects of long-wavelength ultraviolet A1 and visible light on pigmentation and erythema

“…Colorimetry and DRS are noninvasive objective assessment techniques used to quantitatively assess erythema and pigmentation . The details of the equipment have been described previously and are also included in Materials and Methods S1 (see Supporting Information) . In this study, colorimetric analysis focused on the magnitude of the change in L* (−ΔL*).…”

“…9,10 The details of the equipment have been described previously and are also included in Materials and Methods S1 (see Supporting Information). 11,12 In this study, colorimetric analysis focused on the magnitude of the change in L* (ÀDL*). The greater the magnitude of ÀDL*, the darker the lesion.…”

Assessment of skin pigmentation by confocal microscopy: Influence of solar exposure and protection habits on cutaneous hyperchromias

“…In the confocal images, it is possible to observe a regular epidermal honeycomb pattern, the alignment pattern of hyperrefractive basal cells around a nonrefractive papillary dermis in the dermoepidermal junction (DEJ), an increased number of dermal papillae, and a deformation of their alignment pattern . We did not observe any characteristics of inflammatory lesions such as melanophages in postinflammatory hyperpigmentation …”

“…28,29 We did not observe any characteristics of inflammatory lesions such as melanophages in postinflammatory hyperpigmentation. 30 When correlating the daily use of a sunscreen with the level of sun exposure, differences can be observed in the pattern of skin pigmentation of the volunteers in each group.…”

Development and validation of a reproducible model for studying post‐inflammatory hyperpigmentation

“…One interesting model has recently been validated (Isedeh et al, 2016) using 35% trichloroacetic acid (TCA) as inflammatory initiator and found to show clinical and histological similarities to acneinduced PIH. However, the use of TCA at high concentrations may cause significant necrosis of both epidermis and superficial dermis which is not fully controlled.…”