PMC6489026_01
a Clinical features at the first visit. A number of leukoderma lesions were noted on the patient's face. b A biopsy specimen depicted by a spindle-shaped line was taken from the border of a leukoderma on her right cheek. c More abundant repigmentation was obtained on the right side treated with excimer light 10 months after the 1st visit. d, e Close-up views of her right and left cheeks, respectively.
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F1
She was admitted to our hospital because the irregularly shaped hypopigmented macules rapidly extended to her bilateral cheeks, forehead, and area around the lip 4 months after starting to use the cosmetics (Fig. 1a, b). She had a history of systemic sclerosis and was positive for anti-HCV antibody without any current medication. In addition to stopping the use of this cosmetic, phototherapy using excimer light noticeably accelerated repigmentation of the right cheek compared to the untreated left side (Fig. 1c-e).
a The histological findings showed melanocytes apparently decreased in number on not only the lesional but also the perilesional skin (HE staining, original magnification x100). b Immunohistochemical analysis showed no matured melanocytes positive for Melan A (x100). c, d CD4+ (x100) (c) and CD8+ T cells (x100) (d) infiltrated mainly the perifollicular regions, respectively. e Confocal microscopy analysis of cells expressing MITF (red) and FZD4 (green). Nuclei were stained blue with DAPI. MITF- and FZD4-double positive cells (arrows) were observed in the infundibulum of the hair follicle. Inbox High-power magnification view.
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F2
A histopathological analysis of her right cheek lesion before treatment revealed slight inflammation and solar damage in the upper to middle dermis (Fig. 2a). The number of Melan A+ matured melanocytes was apparently decreased not only in the lesional but also in the perilesional skin (Fig. 2b). CD4+ and CD8+ T cells had predominantly infiltrated around the hair follicle, similar to cases of rhododenol-induced (RD) leukoderma, which has recently been of public concern in Japan (Fig. 2c, d). Since FZD4+MITF+ cells were observed in the infundibulum, the FZD4+MITF+ MSCs may supply matured melanocytes to the epidermis and contribute to rapid repigmentation (Fig. 2e).