Pneumocystis jirovecii pneumonia developed in a patient with rheumatoid arthritis after 14 weeks of iguratimod add-on to treatment with methotrexate and etanercept.

A 66-year-old woman who had rheumatoid arthritis and underwent a long-term treatment with methotrexate and etanercept developed Pneumocystis jirovecii pneumonia (PCP) 3 months after iguratimod add-on. Although most rheumatologists might have the impression that iguratimod has less toxicity and immunosuppressive effect compared with methotrexate and biologic disease-modifying antirheumatic drugs, this case suggests that iguratimod may increase the risk of PCP, especially in combination with other drugs.