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.
Melanin is the skin's protective coloring (pigment). Sunburn in a very light-skinned person may occur in less than 15 minutes of midday sun exposure, while a dark-skinned person may tolerate the same exposure for hours. Keep in mind: There is no such thing as a healthy tan.. Unprotected sun exposure causes early aging of the skin and skin cancer.