Finger disformity for as long as I can remember. Does anyone know what this could be?

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I have searched the internet far and wide and i cant seem to find anyone with this same abnormality. The skin seems thinner on the top of my ring finger and i don't know what caused it. It looks totally different to my other fingers and has a purplish tinge. And you can see all the veins in the tip of my finger. Does anyone else have this problem or know what it could be?