RESUMEN
The patient was a 70-year-old woman who underwent transurethral resection of bladder tumor in May 2020. She was diagnosed with urothelial carcinoma (high grade, pT1 by pathology). We started bacillus Calmette-Guerin (BCG) intravesical infusion (80 mg Tokyo strain) in August of the same year after a second transurethral resection. Pain during urination persisted during the administration of BCG, and it worsened after the completion of six doses. The patient was hospitalized with back and neck pain and difficulty in physical movement. At the time of admission, bilateral conjunctivitis was observed. The patient was diagnosed with reactive arthritis associated with BCG intravesical injection therapy, as three typical symptoms were observed (bilateral conjunctivitis, urethritis, polyarthritis). The patient was treated with prednisolone and non-steroidal anti-inflammatory drugs for arthritis, but the symptoms did not improve. We administered salazosulfapyridine and her reactive arthritis improved.