This is the layer of epidermis and dermis that serves as a cover for the nail matrix. It is also called medial. The proximal nail fold is a wedge of thickened skin at the base of the nail. It is found at the bottom of the nail and can be seen on both the fingernails and toenails. It is the skin that folds over the nail matrix and the base of the nail. Around the proximal nail fold is a specialized area called the eponychium  which can be seen on the underside (ventral side), it is where all the dead skin cells are shed and thereby forming the cuticle.
It also has hyponychium which is found at the lateral side which prevents infection from getting under the nail plate. The proximal nail fold is a living skin and it is often mistaken for the cuticle (dead skin cells). The nail matrix is located deep inside this particular structure, the matrix produces the hard part of the nail.
This part of the nail has various functions, such as:
- It serves as an important seal of the nail.
- It helps prevent infection, allergies, pathogens like bacteria, and fungi from getting access to the nail unit and other sensitive parts of the nail bed and matrix.
- It also protects the nail as it grows.