Comparing children and adults with chronic nonbacterial osteomyelitis

Purpose of review To describe the main clinical differences of children and adults with chronic nonbacterial osteomyelitis (CNO). Recent findings CNO is a severe systemic autoinflammatory syndrome characterized by multiple bone lesions because of inflammatory osteitis. Delay to diagnosis of CNO can lead to functional impairment, fractures, and chronic pain. Key clinical aspects and disease patterns differ in children and adults, including onset and time to diagnosis, symptom localization, associated comorbidities (i.e. skin, joints), bone lesion distribution pattern, and treatment approach. Novel biomarkers, such as urine N-terminal telopeptide in children and serum IgG4 in adults, are being studied for possible future use in improving diagnosis and guiding treatment. Despite recent advances in our understanding of CNO, many children and adults have a high disease burden and poor long-term outcomes. Recent findings suggest that adults with CNO tend to have a more chronic disease course and are less likely to achieve remission in follow-up. Summary The clinical presentation of CNO differs in children and adults, highlighting the importance of these key features for the accurate diagnosis and early treatment in CNO.