Acromioclavicular Septic Arthritis and Sternoclavicular Septic Arthritis with Contiguous Pyomyositis

Acromioclavicular (AC) and sternoclavicular (SC) septic arthritis with juxta pyomyositis is rare, with few reports of cases from temperate North America.Pyomyositis has an estimated incidence of 0.5 cases per 100,000 personyears, 1) with only 8% of these in the shoulder 2) and even fewer in the sternocleidomastoid (SCM) muscle.3) Risk factors for both pyomyositis and septic arthritis include diseases such as acquired immunodeficiency syndrome (AIDS), diabetes, intravenous drug abuse (IVDA), and malignancy.4,5) Prompt recognition of pyomyositis and septic arthritis is necessary for proper treatment and prevention of sepsis, chronic osteomyelitis, and even death.Herein, we report two cases, an AC joint and an SC joint infection with contiguous pyomyositis. CASE REPORTSCase 1 A 42-year-old overweight immunocompetent woman with Acromioclavicular (AC) and sternoclavicular (SC) septic arthritis with contiguous pyomyositis are rare, especially in immunocompetent individuals.We report a case of septic AC joint with pyomyositis of the deltoid and supraspinatus muscles and a separate case with septic SC joint with pyomysitis of the sternocleidomastoid muscle.Both patients had similar presentations of infections with Staphylococcus aureus and were successfully treated with surgical incision and drainage followed by prolonged antibiotic therapy.