A Rare Case of Tropical Pyomysitis Acquired on Vacation in a Healthy Male

Pyomyositis has traditionally been considered a tropical disease. Increasing prevalence has been observed in more northern climates, especially with HIV, immunosuppression, and IV drug abuse as predisposing factors. Pyomyositis has the tendency to mimic other conditions, such as muscle contusion, necrotizing fasciitis, or septic arthritis. The rarity of this disease and non-specificity of its symptoms often lead to delay in appropriate diagnosis and treatment.

24-year-old man, seen 2 days prior in orthopedics clinic and the Emergency Department for persistent gluteal pain thought to be due to right-sided sciatica, was admitted following worsening pain, diffuse generalized weakness with polyarthralgias and myalgias These symptoms were associated with night sweats, shaking chills, and difficulty walking. Prior to onset of symptoms, the patient vacationed in Cayman Islands and experienced a stingray bite on his right hand as well as numerous cuts on rocks in stagnant waters. He was febrile with WBC count of 18.7 K/ μL and was found to have methicillin-sensitive Staphylococcus aureus (MSSA); bacteremia. Magnetic resonance imaging (MRI); of his lumbar spine on admission was unremarkable. Repeat MRI 4 days later showed extensive inflammation within musculature with multiple abscesses around right sciatic foramen and septic arthritis of the sacroiliac joint. The patient was subsequently diagnosed with MSSA septic polyarthritis and required several orthopedic procedures. Infectious and oncologic work up was unremarkable. Transesophageal echocardiogram showed 0.3 cm x 0.5 cm aortic valve vegetation, which was managed medically. Repeat MRI 11 days after initiation of appropriate antibiotics and surgeries showed improvement in muscular edema. Based on the MSSA susceptibilities, the patient was treated with 6 weeks of intravenous cefazolin and 2 weeks of oral cephalexin thereafter.

Awareness of tropical pyomyositis in colder climates remains scarce, although cases have been reported in immunosuppressed patients. However, in healthy patients, accurate history of travel and trauma is important in evaluation for predisposing factors for pyomyositis. Early antibiotic and appropriate surgical interventions are imperative for management of this disease in order to prevent systemic toxicity, dissemination of infection, and long-term debility.