What Causes Bruise And Pain In Thumb And Fore Finger?

my niece has throbing pain in rt thumb & rt forefinger. pain is periodical few years back it was felt then subsided & now again it has recurred ther is some ,slight bluish discoloration appears probably along a blood vessel in thumb.pain is aggravated as heart baet increases. my question is what could be the provisinal diagnosis?Is it Raynauds syndrome?