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.
Pigment--a coloring matter in the cells and tissues of the body. Pigmentation--coloring of the skin, hair, mucous membranes, and retina of the eye. Depigmentation--loss of color in the skin, hair, mucous membranes, or retina of the eye. Melanin--a yellow, brown, or black pigment that determines skin color. Melanin also acts as a sunscreen and protects the skin from ultraviolet light.