A 35-year-old man with palmar-plantar psoriasis tested positive for tuberculosis with a tuberculin skin test (TST) prior to starting etanercept therapy. He had not received a BCG vaccination and denied contact with infected people or traveling to tuberculosis-endemic areas. Two subsequent TSTs showed negative results, and a chest radiograph was normal. One month after the last negative TST finding, a QuantiFERON-TB Gold (QFT-G) test (Cellestis Inc, Carnegie, Australia) was performed, and the results were negative. Twelve months after starting etanercept treatment, he showed improvement of his psoriasis and had no evidence of tuberculosis.
Martinez LC, Harrison-Balestra C, Caeiro JP, Nousari CH. The Role of the QuantiFERON-TB Gold Test as Screening Prior to Administration of Tumor Necrosis Factor Inhibitors. Arch Dermatol. 2007;143(6):799–816. doi:10.1001/archderm.143.6.809