Histochemical Study of Melanocytes and Langerhans Cells in Trichrome Non-Segmental Vitiligo

Background: Vitiligo is a frequent acquired depigmenting disorder that causes significant psychological stress.Aim: To study the histopathological changes in the trichrome skin area together with other signs of the disease in the vitiligo skin and the adjacent perilesional skin.Patients and methods: This descriptive study has been performed on thirty cases suffering from vitiligo disease of any duration, with special emphasis on those having the trichrome sign. We used CD1a for identification of Langerhans cells, Melan A for identification of melanocytes, and H&E for changes occurring in vitiligo. Cases were recruited from the dermatology outpatient clinic at Al-Hussein University Hospital, Al-Azhar University, Cairo, from September 2021 till September 2022.Results: The number of melanocyte cells in the vitiligo skin area ranged from 0 to 1 cell/field, representing around 1/3rd the number of cells in the trichrome area and almost 1/9th the cell count in the adjacent perilesional skin. The number of Langerhans cells/field in the trichrome area (11-18 cells) is almost double the count in the adjacent perilesional skin (6-10 cells) and around triple the count in the vitiligo area (2-5 cells).Conclusion: This study found a significant increase in CD1A Langerhans cells in vitiligo-affected areas and trichrome areas, with counts nearly double in trichrome compared to perilesional skin and approximately triple in vitiligo areas. Additionally, the melanocyte count in the trichrome area was notably decreased relative to adjacent perilesional skin.