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.
HP is more common in darker skin. Hyperpigmentation can affect the skin of all races, but is more common and at times more severe and longer lasting in darker skin. The degree of pigmentation in the skin, rather than race or ethnicity, may contribute to developing skin discolorations.