BCG免疫疗法已被推荐用于经尿道切除术后的非肌层浸润性膀胱癌。与BCG相关的肌肉骨骼不良反应很少见。我们报告了两例BCG反应性关节炎的不寻常且难治性严重病例。这两例病例描述了两名男性患者在接受BCG后出现多关节炎。需要经超声引导的糖皮质激素注射、高剂量全身性糖皮质激素以及使用磺胺嘧啶来达到缓解。巴卡卡尔麻散-格瑞链球菌反应性关节炎可表现为小关节和中关节的多关节炎，也可以表现为非对称的踝关节和膝关节的单-寡关节炎，并常伴有腱鞘炎和骨软骨骼炎。BCG促进关节痛和关节炎的机制尚不明确，最被广泛接受的理论是BCG抗原迁移到包括关节在内的不同外围组织。对于风险因素也缺乏了解，可能的遗传因素可能起到了一定作用。正如这两个病例所示，应该考虑将BCG诱导的反应性关节炎纳入接受BCG的患者关节炎和难治性腱鞘炎的鉴别诊断中。 © 2023 亚太风湿病协会联盟和John Wiley & Sons Australia, Ltd.

Intravesical bacillus Calmette-Guérin (BCG) immunotherapy is recommended for non-muscle-invasive bladder cancer after transurethral resection. BCG-associated musculoskeletal adverse events are rare. We report two cases of BCG reactive arthritis that were unusually severe and refractory. These describe two male patients who presented with polyarthritis after BCG exposure. Ultrasonography-guided glucocorticoid injections, high-dose systemic glucocorticoids and the institution of sulfasalazine were required for achievement of remission. Bacillus Calmette-Guérin reactive arthritis can present as polyarthritis of small and medium joints or as mono-oligoarthritis of asymmetrical ankles and knees, frequently associated with tenosynovitis and enthesitis. The mechanism by which BCG promotes arthralgia and arthritis is poorly understood. The most well-accepted theory is that the BCG antigens migrate to different peripheral tissues, including the joints. There is also a lack of knowledge regarding risk factors, with possible genetic factors playing a role. As the two presented cases show, BCG-induced reactive arthritis should be considered in the differential diagnosis of arthritis and refractory tenosynovitis in BCG-exposed patients.© 2023 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.