Identifying key indicators for the clinical diagnosis of bacille Calmette-Guérin Tokyo-172 strain osteomyelitis: two case reports

The insidious nature of BCG-osteomyelitis makes it challenging for clinicians to detect it early on.This 12-year retrospective analysis was conducted at a single tertiary hospital in central Taiwan. Electronic medical records of pediatric patients treated for BCG-osteomyelitis were reviewed. Demographics, clinical features, and laboratory findings were compared with patients diagnosed with culture-proven pyogenic osteomyelitis.In total, eight patients fulfilled our inclusion criteria. Their median age was 16 months, and no obvious gender prevalence was found. Six of the eight patients had lesions involving the lower extremities. When compared with the pyogenic osteomyelitis group, age of disease onset was found to be significantly younger in the BCG osteomyelitis group (p=0.038). Absence of fever and pain in the BCG osteomyelitis group was found to be statistically significant when compared with the pyogenic group (p=0.002 and p=0.026 respectively). CRP and ESR were found to be significantly higher in the pyogenic osteomyelitis group (p=0.000 and p=0.004 respectively).BCG-related osteomyelitis must be considered when evaluating an afebrile child presenting with an unexplainable swelling or limp, and especially when the lesion is located on a lower limb. Laboratory studies may reveal normal WBC and CRP, with a normal to modest elevation of ESR. Imaging studies, including plain radiographs, magnetic resonance imaging (MRI), or computed tomography (CT) should be employed to rule out BCG-related osteomyelitis. Early diagnosis help minimize inappropriate antibiotics use, and may lead to a better outcome.