Current and future advances in practice: SAPHO syndrome and chronic non-bacterial osteitis (CNO).

1. Rheumatol Adv Pract. 2024 Oct 14;8(4):rkae114. doi: 10.1093/rap/rkae114. eCollection 2024. Current and future advances in practice: SAPHO syndrome and chronic non-bacterial osteitis (CNO). Furer V(1), Kishimoto M(2), Tomita T(3), Elkayam O(1), Helliwell PS(4). Author information: (1)Rheumatology Department, Tel Aviv Sourasky Medical Center, School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel. (2)Department of Nephrology and Rheumatology, Kyorin University School of Medicine, Tokyo, Japan. (3)Department of Orthopaedic Biomaterial Science, Osaka University Graduate School of Medicine, Osaka, Japan. (4)Leeds Institute of Rheumatology and Musculoskeletal Medicine, University of Leeds, Leeds, UK. Synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome is a rare, underdiagnosed disease with a wide clinical spectrum. Sterile bone inflammation, predominantly of the anterior chest, and skin manifestations (palmoplantar pustulosis, psoriasis vulgaris and acne) are the key features of SAPHO, which shares certain similarities with SpA. SAPHO is closely related to paediatric chronic non-bacterial osteitis (CNO), a spectrum of autoinflammatory bone diseases. The aetiology of SAPHO is considered multifactorial based on a complex interplay of genetic, immune and infectious factors. Despite the increasing awareness of SAPHO/CNO, diagnostic delay is common, as validated classification and diagnostic criteria are lacking. Treatment of SAPHO represents a challenge and includes anti-inflammatory drugs, antibiotics, bisphosphonates, synthetic conventional DMARDs and off-label use of anti-cytokine biologics and Janus kinase inhibitors. This review summarizes the current diagnostic and practical treatment approach to SAPHO/CNO and highlights the ongoing research endeavours concerning the definition and validation of diagnostic criteria, core domains and treatment. © The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. DOI: 10.1093/rap/rkae114 PMCID: PMC11474108 PMID: 39411288