Yellow nail syndrome.

A 70-year-old man presented with a three-year history of thickened and slow growing, yellow-to-green, discolored fingernails and toenails with loss of lunulae and cuticles. He also had a concurrent history of chronic sinusitis with persistent productive cough. His presentation was consistent with the diagnosis of yellow nail syndrome (YNS), which is a rare disorder classically characterized by the triad of yellow dystrophic nails, lymphedema, and respiratory tract abnormalities but which more frequently manifests with only two of three features. The exact mechanism of YNS remains unknown; however, it is thought to reflect functional and/or anatomic defects in the lymphatic vasculature. Treatment options are limited and often unsuccessful, but spontaneous remission occurs in approximately 30 percent of affected patients.