I have this same thing going on on my right hand. It's my index, middle and ring finger. The darkest one is my index finger. I've been wondering what's wrong. It sort of comes and goes in the past few years. Now I'm worried!
Jennifer
Hello,
Apart from contact dermatitis another possibility that comes to my mind is vascular disorder . Color changes in fingertips is one of the commonest symptom of vascular disorders. Color Doppler of the blood vessels, MRI angiography and arteriography may be done to confirm the diagnosis. My sincere advice would be to consult a vascular surgeon.
I hope it helps. Take care and please do keep me posted if you have any additional doubts. Kind regards.