Etanercept-induced lupus erythematosus presenting as a unilateral pleural effusion.

A 72-year-old man receiving etanercept for the treatment of psoriatic arthritis had an exudative pleural effusion with nonspecific fluid analysis and pleural biopsy findings. He was ultimately found to have drug-induced lupus erythematosus due to the etanercept. The spectrum of autoimmune disease due to the use of tumor necrosis factor inhibitors is reviewed.