I have a black infection (fungus ,I guess) on my left leg below knee. It's too dry. It itches when the environment is wet, If I cut it by blade then it turns like dry powder. It doesn't sense much. When I cut it then feel free from the itching after it bleeds. But after cutting it again grows to the same shape and size within two days. I have this since my childhood. So want to get cured from this irritating infection.