Dermatology question

A friend of mine asked me to do a little research on a problem he's been having for the past 15 years that his doctors havent been able to solve...

15 years ago, he smashed the tip of his little finger on his left hand with a hammer. Since then, the skin at the tip of his finger began to dry and crack... over 15 years it has progressed about midway down his finger AND to his other fingers on that hand starting with the 4th digit and progressing toward the thumb. The drying/cracking/bleeding only goes about halfway down each finger and does not affect his hand. There is no numbness, he has good circulation (rapid cap refill and the hair growth/nail growth & appearance on the fingers of his left hand is the same as on his right hand); he said the tips of his fingers are very tender. The right hand is not affected at all. His doctor thinks it is related to a foot fungus... no medications, moisturizers, etc have helped over the years and the condition is obviously getting worse.

It seems to me that if it were a fungus that he picked up from his foot that it would have affected the right hand as well (he's right handed, afterall!) or at least would have progressed to his hand rather than only affecting his fingers.

Its really rather strange... Have any of you seen anything like this or have any ideas of treatments he might consider?

Thanks for your input!

~~Rachel