Suggest Treatment For Itching Below The Nails

Doctor, I am 50 years of age. On frequent intervals I have itching in both of my toes just below the nails, once the itching stops, the skin thickens, color changes to dark and dry, no discharges. kindly suggest me a treatment. I have undergone PTCA about three years ago and on medication. But the skin problem was first noticed by me about 25 years ago, and then it wasnot that frequent. MOHAN, Tamilnadu, India