P3C308: Back Pain in an Adolescent Male

Introduction: Paraspinal abscesses are a rare cause of lower back pain in children and adolescents and considered medical emergencies. Studies report that the incidence of pediatric paraspinal abscess is approximately 1 in 100,000-250,000. We present one of the first reported cases of back pain secondary to paraspinal abscesses due to Fusobacterium necrophorum.

Case Description: A 17-year-old healthy male presented to the hospital with 2 weeks of worsening lumbar pain. He had no previous trauma. His physical examination revealed he was febrile, tachycardic, had diffuse lumbar paraspinal muscle tenderness worse on the right side with prominent swelling on the right, and had pain with flexion of lumbar spine. Initial admission labs were significant for leukocytosis, elevated inflammatory markers, elevated creatine phosphokinase, and positive COVID-19 PCR. MRI of the lumbar spine revealed multiple 3.0 x 2.6 x 8.3 cm abscesses on the right and 2.5 x 3.1 x 9.1 cm abscesses on the left within the paraspinal muscles extending from L4 to approximately S2-S3 (Figure 1). Given these findings, he underwent ultrasound-guided incision and drainage of the abscesses and placement of Jackson Pratt (JP) drains. Wound cultures grew Fusobacterium necrophorum, and he was treated with clindamycin and ampicillin-sulbactam.

During the hospitalization, laboratory markers down trended, blood culture was negative, and he remained afebrile and asymptomatic from COVID-19. Risk factors for paraspinal abscesses were evaluated including negative HIV serology, negative T-spot, and normal HgbA1c. Repeat MRI demonstrated reduced size of the abscesses, and the drains were removed. He was discharged on hospital day 15 with a peripherally inserted central catheter (PICC) line for a total of 4 weeks of clindamycin and ampicillin-sulbactam.

Discussion: Paraspinal abscesses typically occur in the mid-thoracic or lower lumbar spine of patients with risk factors such as immunocompromised state, diabetes, or spinal trauma. MRI is the gold standard for identifying paraspinal abscesses. Staphylococcus aureus is the most common bacterial organism so empiric antibiotic treatment should provide coverage for methicillin sensitive Staphylococcus aureus (MSSA) and methicillin resistant Staphylococcus aureus (MRSA). Parenteral administration for 4 to 8 weeks is recommended to reduce the risk of osteomyelitis.

Conclusion: This case suggests that Fusobacterium necrophorum should be considered in pediatric patients presenting with paraspinal abscesses despite identifiable risk factors. Providers should be aware of this rare etiology and consider anaerobic coverage for empiric treatment.