The skin(皮膚) separates epidermis(皮) and dermis(膚) in Oriental medicine. epidermis and hair come from ectoderm as dermis comes from mesoderm in embryology. Epidermis and hair belong to the Metal(金) and dermis belongs to the Earth(土) in Oriental medicine. The lung is related to the skin and hair. The skin surface is nourished by the essence from the lung, and the. lung has the function of sending wei-qi(衛氣.: defensive Energy) to the skin surface to guarantee body resistance. The skin takes nourishment from blood(血) and express by qi(氣). The supply of nutrients to the lung and skin relies on the function of the spleen, pancreas and subcutis. Flaming of the heart fire may scorch the essence of the lung-metal, inducing dermatosis.