Hi, My Wife Is Having Cracks On Her Fingers. She

hi,
My wife is having cracks on her fingers. she underwent treatment for infections. once the treatment is on she feels k. once she stops again it starts. sometimes it bleeds from the crack. its on all the finger ends. she underwent patch test, its negative. she avoided detergents and cosmetics too. can it be a deficiency or else.please suggest me some remedies.