ABSTRACT
The nail plate also abbreviated as ‘‘nail,’’ is a hard keratin plate, slightly convex in the longitudinal and the transverse axes. It is set in the soft tissues of the dorsal digital extremity, from which it is separated by the periungual grooves (proximal, lateral, and distal) (Fig. 1) (1-5). It stems from the nail matrix located in the proximal part of the nail apparatus. The nail plate and matrix are partly covered by a skin fold called the proximal nail fold (PNF). The lunula, also known as ‘‘half-moon,’’ is a whitish crescent, visible at the proximal part of some nails and more specifically those of the thumbs and big toes. It corresponds to the distal part of the matrix. From the latter, the nail plate grows toward the distal region sliding along the nail bed to which it adheres closely and from which it only separates at the distal part, called hyponychium. The latter and overhanging free nail provide a crevice, which is a reservoir for microbes.
