Localization of Merkel Cells at Hairless and Hairy Human Skin Sites Using Keratin 18

The study investigated the localization of Merkel cells in human skin, focusing on both hairless and hairy sites, using immunohistochemistry with antibodies against keratins 18 and 19. It was found that Merkel cells were more densely distributed in hairless areas like the palms and soles, specifically at the bottom of the rete ridges in the epidermal basal layer. In contrast, at hairy sites such as breast skin, Merkel cells were located in the interfollicular epidermis and the isthmus region of hair follicles. Despite their known association with sensory nerve fibers and potential role as mechanosensory receptors, the exact origin and function of Merkel cells remained unclear.