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.
Hyperpigmentation â Melasma. When dark pigments seem to appear on the skin, it is known as hyperpigmentation. This is because, the skin starts producing more melanin, which is a pigment responsible to give skin its color. Hyperpigmentation can also be termed as dyschromia or increased pigmentation.There are certain areas of skin wherein melanin is produced in excess, resulting in formation of deposits, which result in producing skin patches that are darker than the skin in the surrounding area.yperpigmentation can also be termed as dyschromia or increased pigmentation. There are certain areas of skin wherein melanin is produced in excess, resulting in formation of deposits, which result in producing skin patches that are darker than the skin in the surrounding area.