Characteristics, Treatment Options, and Outcomes of Chronic Non-bacterial Osteomyelitis in Children

Abstract

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disease most prevalent in children. In this review, we seek to highlight the most recent advances in the understanding of the pathophysiology, treatment, and outcomes of CNO. Recent observations support a pathophysiologic framework involving imbalanced expression of pro-inflammatory versus anti-inflammatory cytokines, thereby inducing increased differentiation and activation of osteoclasts. Although no medication nor protocol is yet specifically indicated in the treatment of CNO, there exists an expanding body of evidence for agents exerting their effects via interference with these pro-inflammatory pathways (namely non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs, bisphosphonates, and biologics), highlighted herein. With an incidence rivaling that of bacterial osteomyelitis, childhood CNO represents an important and growing field of study. Once thought to be benign and self-limiting, CNO is now recognized to follow a relapsing and remitting course in the majority of children, and to carry substantial risk of irreversible growth and bone sequelae. Perhaps of greatest importance to the study of CNO treatment is the recent development of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) consensus treatment plans, the implementation of which will allow for prospective comparative effectiveness studies and, ultimately, the development of standardized treatment protocols.