The nail flag sign in heart transplant recipients: case reports and review of the patients with the flag sign of the nail.

The nail plate flag sign is a distinctive nail plate change that appears as white, red, white, and red sequential transverse bands beginning at the proximal nail fold. This distinctive nail change was initially described in patients with diabetes mellitus and leprosy; indeed, it was considered to be characteristic, but not diagnostic of leprosy. Subsequently, the flag sign was observed in patients with vitiligo. The flag sign has recently been noted in two men following heart transplantation. In summary, the flag sign is a unique nail change that has occurred in patients with autoimmune disorders, infection, and post transplantation surgery associated with immunosuppressive therapy to prevent organ rejection.