ABSTRACT
Transverse overcurvature of the nail describes a deformity where the nail bed progressively pinches distally. Described by Cornelius and Shelley, a pincer nail (also known as a trumpet nail) is a result of transverse distal overcurvature.1 This may occur in both toenails and fingernails; however, the great toenails are more commonly affected.2 The pathophysiology of the pincer nail has not been established. Pincer nails may cause pain during ambulation, wearing shoes, application of light touch, and be cosmetically displeasing to the patient. It is important to distinguish that pincer nails and ingrown nails are not derived from the same pathology, as ingrown nails describe the symptoms of pain and discomfort produced at the nail distally, whereas pincer nails are a distinct morphological entity. Like pincer nails, ingrown nails contain a distal incurvated nail edge, but this symptomatic state is often attributed to improper nail trimming, heredity/the overall shape of the digit, biomechanical deformities such as bunion and hammertoe deformities, and physical forces from ill-fitting shoes.
