Congenital onychodysplasia of the index fingers with a y-shaped bifurcation of the distal phalanx

Congenital onychodysplasia of the index fingers (COIF, Iso and Kikuchi syndrome) is a congenital disorder characterized by various forms of nail dysplasias mainly-involving the index fingers. Its etiopathogenesis is still unknown, but ischemia of the palmar digital arteries has been suggested to play a role in this disorder. Although not specific to it, a Y-shaped bifurcation of the distal affected phalanx is a characteristic finding of this syndrome. In this review, we report a case of COIF who presented with bilateral micronychia with a Y-shaped bifurcation of the distal phalanx.