http://academiadepodologia.com/onicofosis-o-una-encarnada/
https://podologiaaccademia.com/onicofosi-o-unghia-incarnita/
https://podiapaedia.org/wiki/dermatology/nail-disorders/onychophosis/
Onychophosis is a common problem which is the development of a callus or hard skin down the edge of the nail due to pressure between the nail plate and the skin grove down the edge of the nail. A skilful podiatrist can remove it.