Congenital onychodysplasia of the ring finger presenting as a bifid nail.

Congenital onychodysplasia, or Iso-Kikuchi syndrome, is classically defined as a congenital nail abnormality of one or both index fingers that is often associated with a bone abnormality in the affected finger. We report an unusual case of a 6-year-old girl who presented with an S-shaped, bifid nail of the left ring finger that had been present since birth. X-ray findings were used to confirm a diagnosis of congenital onychodysplasia of the ring finger.