Characteristics of patients with yellow nail syndrome and pleural effusion.

Yellow nail syndrome (YNS) can be associated with a pleural effusion (PE) but the characteristics of these patients are not well defined. We performed a systematic review across four electronic databases for studies reporting clinical findings, PE characteristics, and most effective treatment of YNS. Case descriptions and retrospective studies were included, unrestricted by year of publication. We reviewed 112 studies (150 patients), spanning a period of nearly 50 years. The male/female ratio was 1.2/1. The median age was 60 years (range: 0-88). Seventy-eight percent were between 41-80 years old. All cases had lymphoedema and 85.6% had yellow nails. PEs were bilateral in 68.3%. The appearance of the fluid was serous in 75.3%, milky in 22.3% and purulent in 3.5%. The PE was an exudate in 94.7% with lymphocytic predominance in 96% with a low count of nucleated cells. In 61 of 66 (92.4%) of patients, pleural fluid protein values were >3 g/dL, and typically higher than pleural fluid LDH. Pleurodesis and decortication/pleurectomy were effective in 81.8% and 88.9% of cases, respectively, in the treatment of symptomatic PEs. The development of YNS and PE occurs between the fifth to eighth decade of life and is associated with lymphoedema. The PE is usually bilateral and behaves as a lymphocyte-predominant exudate. The most effective treatments appear to be pleurodesis and decortication/pleurectomy.