慢性再発性多発性骨髄炎

Although rare in high-income countries, scurvy remains an important consideration in children with longstanding and highly restrictive eating habits, particularly those with autism spectrum disorder (ASD). Children with scurvy often undergo evaluation for infection, inflammatory bone disease, or malignancy before the diagnosis becomes apparent. This report describes an eight-year-old non-verbal boy with ASD who presented with progressive lower extremity pain and refusal to bear weight or walk. Imaging demonstrated diffuse osteopenia with classic metaphyseal changes of scurvy on radiographs, multiple vertebral compression deformities, and multifocal marrow signal abnormalities on MRI that closely mimicked chronic recurrent multifocal osteomyelitis (CRMO). Further assessment revealed a markedly restricted diet, characteristic skin findings, and a serum vitamin C level < 0.1 mg/dL, confirming the diagnosis of scurvy. Additional nutritional deficiencies of vitamins A, D, and E were identified. Following initiation of nutritional rehabilitation including vitamin C therapy, the patient experienced rapid improvement, with resolution of pain and restoration of weight-bearing ability. This case illustrates that pediatric scurvy can closely mimic CRMO clinically and radiographically, highlighting an important diagnostic pitfall and emphasizing the importance of careful dietary assessment to avoid unnecessary invasive diagnostic procedures.

Background/Objectives: Chronic recurrent multifocal osteomyelitis/chronic nonbacterial osteomyelitis (CRMO/CNO) is an auto-inflammatory bone disease for which optimal treatment and imaging-based monitoring remain incompletely defined. Methods: We conducted a single-center retrospective review of nine pediatric patients with CRMO/CNO treated with tumor necrosis factor inhibitors (TNFis). Clinical improvement was assessed using Visual Analog Scale (VAS) pain scores, erythrocyte sedimentation rate (ESR), and physical examination findings. Radiographic assessment used longitudinal, site-specific magnetic resonance imaging (MRI) scored with a simplified approach adapted from the Chronic Nonbacterial Osteomyelitis Magnetic Resonance Imaging Scoring (CROMRIS) system. Results: Our cohort was composed of six females and three males with a median age of seven years. TNFi monotherapy was initiated as a first-line therapy (n = 4) or step-up (n = 5). During a median follow-up time of 26 months, treatment was tolerated well, except for the emergence of psoriasis in three patients (n = 3), among whom one necessitated treatment change. Eight patients on TNFis achieved clinical remission, including five with complete resolution of MRI lesions. Conclusions: In this small, single-center case series, TNFi monotherapy was associated with sustained disease control, as reflected by clinical improvement and MRI-documented lesion resolution. These findings emphasize the need for validation of our observations in larger multi-center cohorts.

Chronic non-bacterial osteomyelitis/chronic recurrent multifocal osteomyelitis is an autoinflammatory, sterile bone disorder that predominantly affects children but can also occur in adults. The nonspecific nature of its presentation, as well as a relative lack of awareness of the condition, often results in significant diagnostic delay. In this article, we present the case of a female patient who began experiencing sternal pain at the age of 14, initially thought to be due to costochondritis but ultimately discovered to be secondary to chronic non-bacterial osteomyelitis/chronic recurrent multifocal osteomyelitis. We demonstrate her long and tortuous diagnostic journey, including key imaging and bone biopsy findings. We also report good clinical and radiographic response to tumour necrosis factor-α inhibitors, despite having to switch from adalimumab to etanercept and then to methotrexate due to side effects and anti-drug antibody production.

Chronic Recurrent Multifocal Osteomyelitis (CRMO) is a rare autoinflammatory bone disorder that primarily affects children and adolescents. It is characterized by recurrent episodes of bone pain with sterile inflammatory lesions, often resembling infection or malignancy. We present a case of a 12-year-old girl who initially presented with atraumatic right knee pain and was ultimately diagnosed with CRMO after imaging and histopathologic evaluation. Her clinical course was complicated by recurrent episodes, and physeal damage resulted in limb length discrepancy. Early recognition through appropriate imaging and multidisciplinary evaluation helps avoid unnecessary antibiotics and invasive procedures. Long-term follow-up is essential, as persistent inflammation can cause irreversible skeletal complications.