Rashes on both upper hands. Problem.

Rashes appeared on both of my hand 6 to 7 yrs ago. It remains on the same place without spreading on full body. I consulted few dermatologists for this problem but did not satisfy with their medicines. When i applied their medicines it reduced to the point that i could hardly see but again reappear when i stopped applying as none of them told me the time when i should stop using their medicine. After that i found it as a problem of dry skin and at present i am applying normal vaseline moisturising cream on it but story remain same when i stop using it rashes again reappear. I am facing this issue for so long now i want to get relief from this problem. Please help me to sort out this problem. Thank you in advance.