Solitary Pyomyositis of the Left Rhomboideus Muscle Caused byStreptococcus anginosusandStreptococcus intermediusin an Immunocompetent Person

Abstract

Primary pyomyositis is a bacterial infection of the skeletal muscle commonly affecting children with Staphylococcus aureus most often isolated as a pathogen. However, pyomyositis caused by anaerobic bacteria is rare in adults. Here, we report a case of solitary Pyomyositis of the left rhomboideus muscle in an immunocompetent person. A 70-year-old Japanese male presented with high fever and left shoulder pain. His muscle below the lower edge of the left scapula was tender and swollen. His laboratory examinations revealed severe inflammation. Computed tomography showed a solitary low-density area around a contrast enhancement in the left rhomboideus muscle. He was diagnosed as having solitary pyomyositis. Although his symptoms did not improve despite empiric intravenous administration of antibiotics, an incision was performed. Streptococcus anginosus and Streptococcus intermedius were isolated from the culture of drainage fluid. His symptoms gradually disappeared after the incisional drainage and continuous administration of antibiotics. Pyomyositis did not recur after his discharge. To the best of our knowledge, this is the first report on anaerobic pyomyositis of the shoulder muscle.

Staphylococcus aureus Bacteremia With Disseminated Multiple Foci and Pyomyositis in an Immunocompetent Patient: A Case Report

“…The highest incidence of pyomyositis is between 10 and 40 years of age. Pyomyositis usually affects the large muscles in the buttocks and quadriceps, but the shoulders are rarely affected [ 8 , 9 ].…”

“…Advanced stages of pyomyositis often necessitate more invasive procedures, including surgical drainage or percutaneous catheter drainage, which should be performed under the guidance of CT scans or ultrasound, in addition to continued antibiotic therapy [ 14 ]. It's important to highlight that utilizing CT scans or ultrasound to guide the drainage of abscesses has proven effective, serving diagnostic and therapeutic roles [ 8 ].…”