I am 53 year old male, on my left hand, I am having patch of hard skin / dead skin inbetween thumb and Index finger since childhood (perhaps i use to chew / bite that portion during childhood days). This patch is still continuing and look very dirty. At times I scrub this portion of skin to remove the skin layer for better look.It is back again in 1 to 2 months . For the past 3 years I have noticed my knuckles skin in both the hands have developed dark patches of thick skin.Looks very dirty. Please advise remedy for these skin problems.