A twenty-two-month-old boy with septic hip arthritis had persistent elevated inflammatory markers and daily fevers despite multiple antibiotic regimens and repeated surgical debridements yielding negative cultures. After exhaustive work-up for other infectious, rheumatologic, and immunologic etiologies, he met diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH) and developed cultures positive for fungal hip arthritis. Following treatment for HLH and fungal hip arthritis, he improved and was discharged.
No previous report in the literature specifically associates HLH with septic hip arthritis, to our knowledge. Surgeons should suspect underlying immunologic deficiencies and atypical infectious causes of septic arthritis when usual treatment modalities have failed.