Retronychia : four new cases.

Retronychia (RN) refers to the incarnation of the nail plate in the proximal nail fold. We report four clinical cases of this little-known pathology, where there may be a long delay in diagnosis. RN exhibits a triad of clinical features, which are chronic paronychia, liquid discharge from under the nail fold and disruption of the linear nail growth. Chronic paronychia is often confused with bacterial or fungal infection. Empirical antibiotic treatment is not useful. Nail plate avulsion is the diagnostic and curative procedure of choice. Subsequent nail growth is normal without dystrophia and no recurrences are observed. Knowledge of this pathology avoids misdiagnosis, unnecessary antibiotic or local treatments and allows adequate surgical management.