Nail wall

The nail wall is the anatomical term for the skin that forms the lateral and proximal boundaries of the nail unit. It consists of the lateral nail folds (on each side of the nail plate) and the proximal nail fold (at the base of the nail). These folds are composed of epidermis and underlying dermis, and they serve to protect the emerging nail plate and the underlying nail matrix. The ventral surface of the proximal nail fold forms the eponychium, which produces the cuticle that adheres to the nail plate and provides a seal against pathogens and irritants.

The lateral nail folds, together with the proximal nail fold, create a distally open frame that guides and protects the growing nail plate. The nail wall is richly innervated and vascularized, contributing to its sensitivity and role in protecting the nail apparatus.