Four-Year Follow-Up of a Case of Yellow Nail Syndrome With IgM Deficiency.

Yellow nail syndrome is a rare condition occurring sporadically, with an extremely low prevalence rate. This syndrome classically presents with a triad of lower extremity edema, yellow nails, and mucosal issues such as pleural effusion and/or chronic sinusitis. Two out of the three features are deemed sufficient to diagnose a person with yellow nail syndrome. We present a rare case of yellow nail syndrome that began with chronic leg swelling and later progressed to the development of an asymptomatic pleural effusion and finally discoloration of nails. In our case, the patient did have a significant recent history of a total knee replacement with a titanium implant. Of note was the chronology of events including leg edema and asymptomatic pleural effusion which were present even before the titanium knee implant. The third feature of the hardening and yellow discoloration of the nails was found to have developed following the knee replacement. Interestingly, on further evaluation, he was found to have IgM deficiency.