65 | RETRONICHIA UP TO DATE

A. Podo Brunetti, G. Cannata | Dermatologia Clinica, Università Vita-Salute San Raffaele, Milan, Italy

Retronychia is a specific form of post-traumatic ingrown toenail at the proximal nail fold, characterized by the formation of multiple stacked nail plates (polymeronychia). There are three forms of retronychia: acute, with slowed or arrested nail growth, perionychitis, and polymeronychia with or without onycholysis; subacute, which is a continuous or episodic occurrence of retronychia, with perionychia that may slowly subside or worsen. There is chronic polymeronychia with polymeronychia, pachyonychia due to stacked columnar polymeronychia, or onychogryphosis, and a shortened nail due to the disappearance of the distal third of the nail bed. Sometimes the nail has a yellowish color. For chronic retronychia—as a treatment—nail filing performed by a dermatologist is recommended, followed by the application of a cosmetic nail tip, especially in women and during the summer months.