Three cases of palmoplantar pustulosis successfully treated with apremilast

and coincided with the keloid plaque. Although the exact role of KP in vitiligo has not yet been established, various kinds of mechanical trauma have been described in association with the development of vitiligo. Gauthier et al. showed that repeated friction could cause detachment and transepidermal elimination of melanocytes in susceptible patients. Recently, the levels and distribution of E-cadherin, which is responsible for the adhesion between melanocytes and keratinocytes in the epidermis, have been demonstrated to be significantly altered in melanocytes on the non-lesional skin of patients with vitiligo. These studies could explain how mechanical stress causes depigmentation in patients with vitiligo. In the present case, the continuous stretching tension in a keloidal plaque would weaken the adhesion between melanocytes and keratinocytes in the predisposed person. It would result in the development of a new vitiliginous patch on the keloid plaque as a KP. Recent research has paid growing attention to the role of KP in the etiology of vitiligo. In the present case, we demonstrated that the stretching tension of a keloid could be a potential cause of KP in vitiligo as well. To the best of our knowledge, this is the first report of co-localization of vitiligo and a keloid scar, and we believe that the present case could help to broaden our understanding of the relationship between mechanical stress and vitiligo. CONFLICT OF INTEREST: None declared.