Hello Doctor, I have this dry, scaly, and sometimes cracks on one, sometimes two knuckles. It comes and goes, but always appears on the same knuckle on my right index and middle finger s knuckle. It doesn t itch , but does get painful when it cracks. It s only isolated in those areas, and I don t have it anywhere else. I m not sure if there is a correlation, but, it seems to come when I am in the sun for a long periods of time, and then it takes awhile for it to go away with out any treatment. Any ideas? Thank you in advance.