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Updated: Jul 5, 2026

Roller Microneedle Combined with Tranexamic Acid Solution in Treating Melasma
Published on: January 19, 2024
Solar elastosis and presence of mast cells as key features in the pathogenesis of melasma
R Hernández-Barrera1, B Torres-Alvarez, J P Castanedo-Cazares
1Department of Dermatology, Hospital central University of San Luis Potosi, S.L.P, Mexico.
Abstract:
Melasma is an acquired hypermelanosis on sun-exposed areas. Its pathogenesis has not been clearly elucidated. Using histochemistry (Giemsa, Verhoeff-van Gieson and Fontana-Masson staining), we evaluated melasma lesions and compared them with nonlesional skin. Skin samples were obtained from lesional and nonlesional facial skin of 27 patients with melasma, and biopsies were also taken from normal control subjects. Mast cells and solar elastosis areas were evaluated using a computer-assisted image-analysis program. Lesional skin had abundant elastotic material compared with nonaffected skin (13.3 +/- 2.8% vs. 10.2 +/- 2.9%, P < 0.001). Mast cells were more prominent in the elastotic areas of melasma skin (173 +/- 57% vs. 145 +/- 57%, P = 0.04). Melasma could be a result of a cumulative sun exposure, in a microenvironment of cutaneous photoageing in which inflammatory cells, particularly mast cells, play a key role.
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