skin growth under big toenail

Hi I am a 27 yo bf and for some years now I have had growth underneath my big toes (and now have spread to both second toes). There was no trauma or anything that I recall but just one day I just noticed the growth. It appears as if the top layer of skin nearest to the nail bed hardened and has become attached to the nail. When you press on my big toes there is soreness. When grooming and cutting the nails, the nails themself are hard to cut. I tried cutting the skin as I thought maybe it was just hardened dead skin but it hurt really bad. The skin does have feeling and appears to be growing. What can this be? (I have pictures if they are needed).