I have a pea size blue bump on the palm side of my ring finger.  The blue bump is between joints.  I checked your site thinking it is a cyst, but it does not look like any of the photos of cysts.  i have had it for a month and am now concerned because a vein? may be the reason for the blue color.  What could this be?
Hi, If this was not there before, and you have noticed it within few days, and it is single one then it may be injury, insect bite, if no symptoms are there then it may be some skin lesions, ideally it demands the clinical observation still wait for some time, it may go away if not then you will have to see the dermatologist for correct diagnosis, diagnosis of skin lesion can only be possible with clinical examination. Hope this information helps. Let me know if I can assist you further.