Yellow Nail Syndrome: A Differential Diagnosis That Must Be in Mind.

Yellow nail syndrome (YNS) is a rare disorder that consists of a clinical triad of thickened yellow nails, lymphedema, and recurring respiratory symptoms. These findings can occur simultaneously or additively, and the characteristic nail changes are an obligatory feature for the diagnosis. The diagnosis of YNS is one of exclusion, and although it is more often an isolated condition, it can occur secondary to immune or neoplastic disorders. Involvement of the respiratory tract occurs in most cases and has a diverse clinical presentation, including pleural effusion and recurrent pneumonia. Due to the rarity of this syndrome and the limited availability of effective treatments, YNS remains associated with substantial morbidity. We present a case of a 58-year-old woman who had a history of recurrent pneumonia, chronic sinusitis, arthralgias, and yellow dystrophic nails that was diagnosed with YNS, and in which daily supplementation with vitamin E resulted in a remarkable clinical improvement.