Abnormal nail shape Ragged cuticle 2016-04-11T22:02:34Z The cuticle (properly known as the eponychium, or the medial nail fold or the proximal nail fold), is the thickened layer of skin surrounding fingernails and toenails. Its function is to protect the area between the nail and epidermis from exposure to bacteria. This term refers to the presence of and irregular edge or outline of the cuticle. UMLS:C4280756