Case Presentation: A 71-year-old male with a PMH of HTN, HLD, tongue cancer, GERD, CAD, and BPH presented to the hospital with a chief complaint of right-side shoulder pain, erythema, and warmth that started two days prior. Two days before noticing these symptoms, he had undergone an EGD without complications where he had a peripheral IV placed in the dorsal surface of his right hand. Initially, when his symptoms started, he went to an urgent care and was treated with amoxicillin and oral steroids. The patient denied any recent trauma to his arm or shoulder.
Presenting vitals were stable with a temperature of 98.3 F. Physical exam revealed erythema and warmth from the distal lateral humerus extending up near the proximal lateral humerus, supraclavicular region, and anterior shoulder. Labs revealed a white blood cell count of 14,100 / µL, and X-Ray of the right shoulder revealed a small ossification along the lateral aspect of the humeral head which may have been an indication of calcific tendinitis or bursitis. Blood cultures had no growth.
The patient was admitted to the hospital for cellulitis and started on IV vancomycin. The patient developed worsening shoulder pain with movement. A CT scan of the Humerus/Right Arm with IV contrast revealed complex fluid collections in the musculature of the anterior aspect of the right shoulder involving the deltoid muscle extending into the musculature of the anterior aspect of the right arm likely involving the biceps muscle measuring 4.6 cm by 4.4 cm by 12.9 cm.
General surgery was consulted and took the patient the same day for debridement and abscess drainage, and a large amount of pus was expressed from the wound which later grew MRSA. The patient improved dramatically after surgery and was discharged with oral linezolid.
Discussion: Pyomyositis is a purulent infection of the skeletal muscles that arises from hematogenous spread, usually with abscess formation. Pyomyositis is classically an infection of the tropics, although it has been recognized in temperate climates with increasing frequency. Most patients with tropical pyomyositis are otherwise healthy without underlying comorbidities, while most patients in temperate regions are immunocompromised or have other serious underlying conditions. Predisposing factors for pyomyositis include immunodeficiency, trauma, injection drug use, concurrent infection, and malnutrition.
Our patient with pyomyositis had a unique presentation as he did not have any predisposing factors, and the most likely source of his pyomyositis was transient bacteremia from a peripheral IV the patient had placed one week prior to presentation for an elective upper endoscopy.
Conclusions: Our case illustrates that while peripheral IVs are generally safe, blood stream infections can occur in approximately 0.1% of peripheral IVs placed, and it is important for clinicians to recognize peripheral IVs as a possible source of bacteremia and infection including pyomyositis.