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EJD, vol. 28, n◦ 4, July-August 2018 In 2008, NPPK was characterized as an entity distinct from Meleda disease, based on its milder clinical manifestations and lack of associated SLURP-1 mutations [3]. In the initial report, our patient was diagnosed based on these characteristics. Since disruption of the SERPINB7 gene was shown to cause NPPK, we verified that our patient had bona fide NPPK through DNA sequencing analysis [2] (figure 1A). Following our initial report, two more reports have described MM occurring in NPPK [4, 5]. Remarkably, one of these included concurrent bilateral occurrence in the feet [4]. All these reports support the contention that NPPK may predispose to MM. MM has been reported not only in NPPK, but also in other types of palmoplantar keratodermas (PPK) [6]. This raises the possibility that PPK lesions can impair immunity against melanomagenesis. Notably, a study on PapillonLefevre syndrome, an inherited PPK, revealed decreased antioxidant and increased oxidative markers [7]. Another group performed research on pachyonychia congenita with Krt16-deficient mouse, which manifest with PPK. The severity of PPK was positively correlated with the activity of Nrf-2 product, which controls antioxidant response [8]. Hence, it is possible that the hyperkeratotic thickening of PPK reflects the severity of inflammatory and oxidative stress which deteriorates the locoregional microenvironment. In one of the reports on NPPK-associated MM, the epidermis of NPPK did not harbour Langerhans cells, the dermal antigen-presenting cells, which are known to be depleted in chronic inflammation [5, 9]. These findings may play some role in melanomagenesis. In conclusion, we report the follow-up of a patient with genetically-confirmed NPPK who experienced recurrent MM. Careful follow-up should be performed for patients with NPPK after surgical resection of MM.