Suspected disk space infection with negative microbiological tests-report of eight cases and comparison with documented pyogenic discitis.

UNLABELLED: Few data are available on patients with suspected noniatrogenic pyogenic discitis but negative microbiological tests.
OBJECTIVES: To compare the features, treatment, and outcomes in patients with suspected versus microbiologically documented noniatrogenic pyogenic discitis. PATIENTS: A retrospective chart review identified eight patients with suspected noniatrogenic pyogenic discitis managed at our institution over a 15-year period. Eighteen age- and sex-matched patients with microbiologically documented noniatrogenic pyogenic discitis managed at our institution during the same period served as controls.
RESULTS: The eight cases had a longer time to diagnosis, a greater risk of abscess formation or epidural infection, and a smaller number of cutaneous portals of entry, as compared to the controls. None of the cases had evidence of endocarditis or diabetes mellitus. Infection at another site preceded the discitis in half the cases. Empirical treatment with two antimicrobials (usually a fluoroquinolone with a beta-lactam or fosfomycin) ensured a full recovery in all eight cases, with no relapses or long-term recurrences, whereas relapses occurred in three of the 18 controls treated with antibiotics selected by antibiotic susceptibility testing.
CONCLUSION: Noniatrogenic pyogenic discitis with negative microbiological studies is associated with distinctive clinical features consistent with smoldering infection. The outcome is favorable under empirical two-drug antimicrobial therapy, usually including a fluoroquinolone given by the intravenous route.