854 - Occult Presentation of Spinal Epidural Abscess

Case Diagnosis: An 87-year-old man diagnosed with left psoas and spinal epidural abscess.

Case Description: An 87-year-old man with a history of chronic back pain presented to the emergency department with acute worsening of back pain for two weeks. He denied acute trauma, but he underwent cystoscopy three weeks prior with an isolated fever the following day. Pyuria was detected at presentation and subsequent culture grew Streptococcus, treated with cephalexin. He re-presented the following week for worsened back pain without neurological deficits or lab abnormalities aside from c-reactive protein of 20 mg/dL. CT spine showed degenerative changes and was discharged with oxycodone and neurosurgery referral. One week later he re-presented with unresolving pain and weakness with an elevated erythrocyte sedimentation rate (138 mm/hr). Admission MRI demonstrated left psoas myositis with abscess and L4-L5 discitis/osteomyelitis with epidural abscess. Serum testing was unremarkable. Infectious disease and orthopedics consults recommended biopsy of the psoas abscess, which grew Streptococcus gallolyticus pasteuranius. He was discharged with ceftriaxone for six weeks.

Discussions: While lower back pain is common in elderly patients, the differential for acute on chronic back pain should always remain broad, even when workup may initially be unremarkable. While leukocytosis is a common feature of SEA (60-80% of cases), its absence, such as in this case, does not exclude SEA as a diagnosis.

Conclusions: Spinal epidural abscess is an uncommon disease that can lead to severe increase in morbidity and mortality if not appropriately diagnosed and treated. While typically patients will present with back pain, fevers, and neurologic deficits with a leukocytosis and elevated inflammatory markers, this may not always be the case. and treatment typically includes 6 weeks of antibiotics with possible need for surgical intervention if there is neurological involvement.