Carpal Tunnel Syndrome And Tarsal Tunnel Syndrome Carpal tunnel syndrome is a condition in which irritation of the wrist's median nerve causes tingling and numbness of the thumb,...learn more Â». In This Article.
1 Argyria-characterised by a metallic, slate-grey or blue-grey pigmentation. 2  The hyperpigmentation is most apparent in the UV-exposed areas of skin, especially the forehead, nose, and hands, as well as mucous membranes. 3  Argyria results from prolonged contact with or ingestion of silver salts.
Skin color. 1  Melanin: It is brown in color and present in the basal layer of the epidermis. 2  Melanoid: It resembles melanin but is present diffusely throughout the epidermis. 3  Carotene: This pigment is yellow to orange in color. It is present in the stratum corneum and fat cells of dermis and superficial fascia.