PDF(Pubmed)
Abstract：
BACKGROUND: Pyomyositis is a microbial infection of the muscles and contributes to local abscess formation. Staphylococcus aureus frequently causes pyomyositis; however, transient bacteremia hinders positive blood cultures and needle aspiration does not yield pus, especially at the early disease stage. Therefore, identifying the pathogen is challenging, even if bacterial pyomyositis is suspected. Herein, we report a case of primary pyomyositis in an immunocompetent individual, with the identification of S aureus by repeated blood cultures.
METHODS: A 21-year-old healthy man presented with fever and pain from the left chest to the shoulder during motion. Physical examination revealed tenderness in the left chest wall that was focused on the subclavicular area. Ultrasonography showed soft tissue thickening around the intercostal muscles, and magnetic resonance imaging with short-tau inversion recovery showed hyperintensity at the same site. Oral nonsteroidal anti-inflammatory drugs for suspected virus-induced epidemic myalgia did not improve the patient\'s symptoms. Repeated blood cultures on days 0 and 8 were sterile. In contrast, inflammation of the soft tissue around the intercostal muscle was extended on ultrasonography.
METHODS: The blood culture on day 15 was positive, revealing methicillin-susceptible S aureus JARB-OU2579 isolates, and the patient was treated with intravenous cefazolin.
METHODS: Computed tomography-guided needle aspiration from the soft tissue around the intercostal muscle without abscess formation was performed on day 17, and the culture revealed the same clone of S aureus.
RESULTS: The patient was diagnosed with S aureus-induced primary intercostal pyomyositis and was successfully treated with intravenous cefazolin for 2 weeks followed by oral cephalexin for 6 weeks.
CONCLUSIONS: The pyomyositis-causing pathogen can be identified by repeated blood cultures even when pyomyositis is non-purulent but suspected based on physical examination, ultrasonography, and magnetic resonance imaging findings.
METHODS: A 21-year-old healthy man presented with fever and pain from the left chest to the shoulder during motion. Physical examination revealed tenderness in the left chest wall that was focused on the subclavicular area. Ultrasonography showed soft tissue thickening around the intercostal muscles, and magnetic resonance imaging with short-tau inversion recovery showed hyperintensity at the same site. Oral nonsteroidal anti-inflammatory drugs for suspected virus-induced epidemic myalgia did not improve the patient\'s symptoms. Repeated blood cultures on days 0 and 8 were sterile. In contrast, inflammation of the soft tissue around the intercostal muscle was extended on ultrasonography.
METHODS: The blood culture on day 15 was positive, revealing methicillin-susceptible S aureus JARB-OU2579 isolates, and the patient was treated with intravenous cefazolin.
METHODS: Computed tomography-guided needle aspiration from the soft tissue around the intercostal muscle without abscess formation was performed on day 17, and the culture revealed the same clone of S aureus.
RESULTS: The patient was diagnosed with S aureus-induced primary intercostal pyomyositis and was successfully treated with intravenous cefazolin for 2 weeks followed by oral cephalexin for 6 weeks.
CONCLUSIONS: The pyomyositis-causing pathogen can be identified by repeated blood cultures even when pyomyositis is non-purulent but suspected based on physical examination, ultrasonography, and magnetic resonance imaging findings.
摘要：
背景：化脓性肌炎是肌肉的微生物感染，有助于局部脓肿的形成。金黄色葡萄球菌经常引起化脓性肌炎;然而，一过性菌血症阻碍血培养阳性，针吸不产生脓液，尤其是在疾病的早期阶段。因此,识别病原体很有挑战性，即使怀疑是细菌性化脓性肌炎。在这里，我们报告一例原发性化脓性肌炎患者，通过重复血液培养鉴定金黄色葡萄球菌。
方法：一名21岁的健康男性在运动过程中出现发热和从左胸部到肩部的疼痛。体格检查显示左胸壁有压痛，主要集中在锁骨下区域。超声检查显示肋间肌周围软组织增厚，具有短tau反转恢复的磁共振成像在同一部位显示出高强度。口服非甾体抗炎药治疗疑似病毒引起的流行性肌痛并不能改善患者的症状。在第0天和第8天重复的血液培养是无菌的。相比之下,在超声检查中,肋间肌周围软组织的炎症得以扩展.
方法：第15天血培养呈阳性，揭示甲氧西林敏感的金黄色葡萄球菌JARB-OU2579分离株，患者接受头孢唑林静脉注射治疗。
方法：在第17天，从肋间肌周围无脓肿形成的软组织进行计算机断层扫描引导下的针吸，培养显示金黄色葡萄球菌的相同克隆。
结果：该患者被诊断为金黄色葡萄球菌引起的原发性肋间化脓性肌炎，并成功地用头孢唑林静脉注射2周，然后口服头孢氨苄6周。
结论：即使化脓性肌炎是非化脓性的，但根据体格检查怀疑，也可以通过反复的血液培养来鉴定引起化脓性肌炎的病原体。超声检查,和磁共振成像的发现。
方法：一名21岁的健康男性在运动过程中出现发热和从左胸部到肩部的疼痛。体格检查显示左胸壁有压痛，主要集中在锁骨下区域。超声检查显示肋间肌周围软组织增厚，具有短tau反转恢复的磁共振成像在同一部位显示出高强度。口服非甾体抗炎药治疗疑似病毒引起的流行性肌痛并不能改善患者的症状。在第0天和第8天重复的血液培养是无菌的。相比之下,在超声检查中,肋间肌周围软组织的炎症得以扩展.
方法：第15天血培养呈阳性，揭示甲氧西林敏感的金黄色葡萄球菌JARB-OU2579分离株，患者接受头孢唑林静脉注射治疗。
方法：在第17天，从肋间肌周围无脓肿形成的软组织进行计算机断层扫描引导下的针吸，培养显示金黄色葡萄球菌的相同克隆。
结果：该患者被诊断为金黄色葡萄球菌引起的原发性肋间化脓性肌炎，并成功地用头孢唑林静脉注射2周，然后口服头孢氨苄6周。
结论：即使化脓性肌炎是非化脓性的，但根据体格检查怀疑，也可以通过反复的血液培养来鉴定引起化脓性肌炎的病原体。超声检查,和磁共振成像的发现。
