What is it such?

[Cidor]

On a medial surface of a distal phalanx of a long finger there was a local dryness (about 0.5 sm2) - the crack, a crack has begun to live, but on a skin has appeared lihinifikatsija (if I still remember something), there was a crack. All lasts is more month, ate vitamins (tsentrum, Vit And, selmevit).
Nothing is scratched, but the crack hurts.
What is it can be?

[Bormotov]

It is necessary for you to make the analysis on mushrooms.