Nail Folds

The skin does not end at the nail plate. Instead it folds underneath and covers the emerging nail plate. This skin fold protects the new, emerging nail plate. This fold is part of the nail unit. It is called the proximal nail fold. Proximal means “nearest attached end.” The skin on either side of the nail plate is an extension of the proximal nail fold, called the lateral nail fold. In this case, lateral means “to the side.” Normally, the proximal nail fold has the appearance of smooth, healthy skin. It can be injured by cuts, nicks and bruises, or irritating chemicals. Once the proximal nail fold is damaged, bacteria, fungi, or viruses can attack and cause infection. The proximal nail fold forms a seal or barrier that protects the area where the nail plate is made.