Cuticle (Eponychium) of Fingernail

Last updated: Nov 20th, 2024

The cuticle or eponychium of the fingernail is a specialized form of epidermis that is found over the base of the nails of the fingers. It is a thin layer of skin that covers the nail plate and nail root just before the nail emerges at the surface, where the keratinized cells will be completely developed. However, the cuticle is not made up of cells but is rather a secretion of the epidermal cells, coating the end of the skin on top of the nail body. It brings the skin on the finger and the nail plate together to provide a barrier that's waterproof.

Beneath the eponychium is the membranous pterygium, providing further protection to the skin against bacteria and infection. The eponychium folds over the top of and back in on the lower edge of the epidermal cells at the junction with the nail. Just beyond the cuticle, particularly on the thumb, the nail body may be whitish or lighter in color in a small hemisphere called a lunula.