Morphological Relationship between Nerve Fibers and Melanocytes in the Epidermis of Melasma

A close contact between melanocytes and nerve fibers in the epidermis has been demonstrated in normal human skin. The interactions between the neural and immune systems play an important role in the pathophysiology of certain dermatoses. In this study, we investigated the intraepidermal nerve fibers and their contacts with melanocytes in the lesions of melasma using double labeled immunofluorescency and confocal laser scanning microscopy. We found that the percentage of contacts between intraepidermal nerve fibers and melanocytes in the lesion of melasma were 74%, significantly more than the 42% in the normal controls (p<0.05). The percentage of melasma lesions was also more than the 69% in the normal-appearing skin of the melasma patients (p<0.05). Our results of the increased contacts between the nerve fibers and melanocytes in the lesions of melasma suggest a potential coordination between the neural and cutaneous immune systems.