Ticking, heating and tingling sensations resulting in discomfort and sometimes pain or pruritus characterize reactive, sensitive skin. These reactions can originate from physical factors, i.e., UV rays, heat, cold and wind; chemical factors such as cosmetics, soap, water and pollution; psychological stress; or hormones, i.e., the menstrual cycle. From a biological view, these phenomena impact the nervous system, for example, involving C-nerve fibers located in the papillary dermis and epidermis.