The skin is human body's widest organs. It performs important physiological functions: protection from germs intrusion by a “barrier effect” and from UV rays of the sun by absorbing it, regulation of body's temperature and excretion through sweat glands and skin vessels, vitamin D synthesis with the help of UV rays, and sense of touch, thanks to a very rich innervation [1-3]. The skin is composed of three main layers: hypodermis, which is made up by adipocytes and is responsible for energy storage and thermic isolation; dermis, in which blood vessels, sweat glands and nerve fibres are located; and epidermis, itself composed of different layers of cells. Keratinocytes and melanocytes are situated in the latter: each melanocyte provides melanosomes, an organelle producing melanin, to several keratinocytes [2, 3].