Near-miss Osteomyelitis in an Immunosuppressed Crohn’s Disease Patient: Diagnostic Vigilance Sparked by a Medical Student

Crohn's disease (CD) patients on immunosuppressive therapy are at increased risk of infections, including osteomyelitis, which could be diagnostically challenging. This case highlights the importance of medical student vigilance in making a near-miss diagnosis of osteomyelitis in a CD patient. A 56-year-old CD patient developed left shoulder pain following localized muscle injection and was initially managed as a soft-tissue abscess. The condition worsened despite 21 days of antibiotics. Investigation: Cultures were positive for methicillin-sensitive Staphylococcus aureus (MSSA). Persistent pain and new neurologic complaints prompted an MRI (T1 hypointensity, T2-STIR hyperintensity, post-contrast enhancement) at 60 days, in support of osteomyelitis without bone biopsy. Management/Outcome: The patient received 6 weeks of intravenous vancomycin (1 g every 12 hours), followed by oral antibiotics, resulting in partial relief of pain (pain score: 8/10 to 4/10) and improvement in shoulder function (Constant-Murley score: 30 to 65 at 3 months). Immunotherapy (adalimumab) was restarted after infection control. This case highlights three practical lessons: maintaining a low threshold for advanced imaging in immunosuppressed patients with persistent pain; incorporating diagnostic time-outs to invite trainee perspectives; and seeking early infectious-disease consultation when osteomyelitis is suspected.