O’Leary D, Wilson AG, MacDermott EJ, et al. - In the present study, the researchers sought to provide a detailed phenotypic description of children and adolescents with chronic nonbacterial osteomyelitis (CNO) who attended tertiary paediatric rheumatology services in Ireland between September 2017 and September 2019, as well as their disease course, treatment and outcomes. A total of 44 children and adolescents were enlisted. This national cohort demonstrated a high prevalence of extraosseous involvement as well as a low response rate to nonsteroidal anti-inflammatory drug treatment. This could indicate a more inflammatory phenotype, emphasising the importance of distinguishing different subtypes of CNO.