After I started to use computer for longer period... A part of my wrist (below palm) is darkening... My keyboard is on a wooden table painted... Even though I wash my hand it's not going... What to do to get rid of the darkening (darkening looks like elbow darkening or ankle side bone darkening). It was only in the right wrist... That I use to type and work with mouse... Now even the left is developing the same darkening thing... Wats the cause and remedy