¹Dr.Sumaiya Iqbal

¹SKMC

Background(s): Chronic nonbacterial osteomyelitis(CNO) is a primary autoinflammatory bone disease that presents more frequently in children and is characterized by inflammatory bone lesions in the absence of an infectious etiology. The aim of this study is to evaluate the demographic, clinical, laboratory, imaging, histopathologic characteristics, and treatment responses of children with CNO

Method(s): We carried out a retrospective single-center case series study of pediatric and adolescent patients treated for CNO between 2022-2023 at a tertiary center in Abu Dhabi. EMR was reviewed in order to collect data.  Analysis was done using excel sheet.

Result(s): 6 patients were included in the study, out of which 83.3% were females. The median current age and age of disease onset was 10.5 years range: 5-14 and 5.5 years range: 4-11.All patients had a pattern of recurrent multifocal disease with bone pain and arthralgia. 66% of patients presented with leg (hip, knee) pain, 33.3% presented with limping, 16.6% had back pain, 16.6% had shoulder pain.Mean ESR was 44.6mm/hr.Median CRP was 12 mg/L with 60% of patients with CRP > 5 mg/L.  25% of patients had positive RF and all had negative antinuclear antibodies and negative HLA-B27.The most common affected sites were metaphysis, diaphysis of long bones including tibia 100%, fibula 80%, femur 60%, humerus 60%, thoracic spine 60% and lumbar spine 40%. It was represented on wbMRI as bone marrow edema and multifocal bone marrow signals—hyperintense signal on STIR and hypointense on T1W.Bone marrow biopsy was done for 2 patients and showed cellular marrow with maturing trilineage hematopoiesis.All received treatment with NSAIDs and responded well. Of the patients whose disease was not controlled with NSAIDs, 3 patients received bisphosphonates and achieved remission

Conclusion(s): The diagnosis of CNO should include clinical history, laboratory and imaging examination, and histopathological examination. Other causes of chronic bone pain should be ruled out. For treatment, NSAIDs are used as first-line drugs followed by steroids,bisphosphonates, and TNF-α inhibitors. Combination therapy with bisphosphonates and TNF-α inhibitors may be an option for refractory CNO. The limitation of this study is its small sample size.  Thus, further studies including more patients from other tertiary centers are required to formulate diagnostic and treatment strategies for CNO