{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T09:19:53Z","timestamp":1787822393824,"version":"build-2784847793"},"reference-count":27,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T00:00:00Z","timestamp":1787788800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Reference Network on Connective Tissue and Musculoskeletal Disease\u2014ERN-ReCONNET"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Chronic nonbacterial osteomyelitis (CNO) is a rare pediatric autoinflammatory bone disease with variable presentation and frequent diagnostic delay. Data from Latvia are limited. This study aimed to evaluate demographic data, clinical manifestations, and treatment strategies of CNO in Latvia. Materials and Methods: This is a retrospective case series study of patients under 18 years of age diagnosed with chronic nonbacterial osteomyelitis (CNO) in the only pediatric tertiary hospital in Latvia between 2014 and 2025. Results: Thirteen patients were identified, 8 boys and 5 girls, with a median age at onset of 10 years. The pooled incidence was 0.31 per 100,000 children. The median time from symptom onset to diagnosis was 4.1 months. All patients had localized bone pain; most had fever, swelling, or a reduced range of motion. Multifocal disease occurred in all patients, with a median of 6 bones involved, and 61.5% had axial skeleton involvement. The most affected bones were the femur and tibia. Extraosseous manifestations included rash, central nervous system involvement, and lung granulomas. The most common comorbidities observed were inflammatory bowel disease and juvenile idiopathic arthritis (JIA). Inflammatory markers were moderately to markedly elevated. Whole body MRI with DWIBS was performed in all patients and showed bone marrow edema and STIR\/T2 FS hyperintense lesions. All patients received NSAIDs, but only 15.4% had a complete response. Many required escalation to second-line treatment with methotrexate, TNF alpha inhibitors, or bisphosphonates. Conclusions: The incidence was similar to that reported in Europe. The cohort was characterized by multifocal, often severe disease with frequent fever and elevated inflammatory markers. Second-line treatment with methotrexate, TNF alpha inhibitors, or their combination showed a robust treatment response.<\/jats:p>","DOI":"10.3390\/medicina62091642","type":"journal-article","created":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T08:02:27Z","timestamp":1787817747000},"page":"1642","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Chronic Nonbacterial Osteomyelitis in Latvia from 2014 to 2025: Case Series"],"prefix":"10.3390","volume":"62","author":[{"given":"Agnese","family":"Grin\u0113vi\u010da","sequence":"first","affiliation":[{"name":"Faculty of Residency, Riga Stradins University, LV-1007 Riga, Latvia"},{"name":"Department of Education and Science, Children\u2019s Clinical University Hospital, LV-1004 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krist\u012bne","family":"Rasa","sequence":"additional","affiliation":[{"name":"Department of Pediatric Rheumatology, Children\u2019s Clinical University Hospital, LV-1004 Riga, Latvia"},{"name":"Department of Pediatrics, Riga Stradins University, LV-1004 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zane","family":"D\u0101vidsone","sequence":"additional","affiliation":[{"name":"Department of Pediatric Rheumatology, Children\u2019s Clinical University Hospital, LV-1004 Riga, Latvia"},{"name":"Department of Pediatrics, Riga Stradins University, LV-1004 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,27]]},"reference":[{"key":"ref_1","unstructured":"Petty, R.E., Laxer, R., Lindsley, C., Wedderburn, L., Fuhlbrigge, R., and Mellins, E. (2021). Textbook of Pediatric Rheumatology, Elsevier-OHCE. [8th ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1186\/1546-0096-11-47","article-title":"Autoinflammatory bone disorders with special focus on chronic recurrent multifocal osteomyelitis (CRMO)","volume":"11","author":"Hedrich","year":"2013","journal-title":"Pediatr. Rheumatol. Online J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1956","DOI":"10.3899\/jrheum.160256","article-title":"Chronic Nonbacterial Osteomyelitis: Pathophysiological Concepts and Current Treatment Strategies","volume":"43","author":"Hofmann","year":"2016","journal-title":"J. Rheumatol."},{"key":"ref_4","first-page":"329","article-title":"Subacute and chronic \u201csymmetrical\u201d osteomyelitis","volume":"15","author":"Giedion","year":"1972","journal-title":"Ann. Radiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2162","DOI":"10.1093\/rheumatology\/keae447","article-title":"Incidence of chronic recurrent multifocal osteomyelitis in children and adolescents in the UK and Republic of Ireland","volume":"64","author":"Chia","year":"2025","journal-title":"Rheumatology"},{"key":"ref_6","first-page":"2301","article-title":"SAPHO syndrome: Current clinical, diagnostic and treatment approaches","volume":"44","author":"Sari","year":"2024","journal-title":"Rheumatol. Int."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1093\/rheumatology\/key143","article-title":"The multifaceted presentation of chronic recurrent multifocal osteomyelitis: A series of 486 cases from the Eurofever international registry","volume":"57","author":"Girschick","year":"2018","journal-title":"Rheumatology"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1007\/s11926-017-0645-9","article-title":"Chronic Recurrent Multifocal Osteomyelitis and Related Diseases\u2014Update on Pathogenesis","volume":"19","author":"Cox","year":"2017","journal-title":"Curr. Rheumatol. Rep."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1186\/s12969-016-0109-1","article-title":"Chronic recurrent multifocal osteomyelitis (CRMO)\u2014Advancing the diagnosis","volume":"14","author":"Roderick","year":"2016","journal-title":"Pediatr. Rheumatol. Online J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1523","DOI":"10.1093\/jbmr\/zjae141","article-title":"An improved understanding of pediatric chronic nonbacterial osteomyelitis pathophysiology informs current and future treatment","volume":"39","author":"Roberts","year":"2024","journal-title":"J. Bone Min. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1093\/rheumatology\/kel190","article-title":"Classification of non-bacterial osteitis: Retrospective study of clinical, immunological and genetic aspects in 89 patients","volume":"46","author":"Jansson","year":"2007","journal-title":"Rheumatology"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1002\/art.43137","article-title":"EULAR\/American College of Rheumatology Classification Criteria for Pediatric Chronic Nonbacterial Osteomyelitis","volume":"78","author":"Zhao","year":"2026","journal-title":"Arthritis Rheumatol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1150","DOI":"10.1111\/j.1651-2227.2011.02205.x","article-title":"Nonbacterial osteitis in children: Data of a German Incidence Surveillance Study","volume":"100","author":"Jansson","year":"2011","journal-title":"Acta Paediatr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1128","DOI":"10.1002\/art.39013","article-title":"A large national cohort of French patients with chronic recurrent multifocal osteitis","volume":"67","author":"Wipff","year":"2015","journal-title":"Arthritis Rheumatol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1007\/s44197-025-00466-y","article-title":"Chronic Non-Bacterial Osteomyelitis in Pediatric Patients: Findings from Multiple Centers in Saudi Arabia","volume":"15","author":"Alahmadi","year":"2025","journal-title":"J. Epidemiol. Glob. Health"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1186\/s13075-021-02658-w","article-title":"First-year follow-up of children with chronic nonbacterial osteomyelitis-an analysis of the German National Pediatric Rheumatologic Database from 2009 to 2018","volume":"23","author":"Reiser","year":"2021","journal-title":"Arthritis Res. Ther."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e269450","DOI":"10.1136\/bcr-2025-269450","article-title":"When fever comes first: An unusual presentation of chronic non-bacterial osteomyelitis","volume":"18","author":"Karam","year":"2025","journal-title":"BMJ Case Rep."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1186\/s13244-021-01059-6","article-title":"Imaging in non-bacterial osteomyelitis in children and adolescents: Diagnosis, differential diagnosis and follow-up-an educational review based on a literature survey and own clinical experiences","volume":"12","author":"Schaal","year":"2021","journal-title":"Insights Imaging"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"170","DOI":"10.4103\/jpgm.JPGM_23_18","article-title":"Chronic nonbacterial osteomyelitis from a tertiary care referral center","volume":"64","author":"Gupta","year":"2018","journal-title":"J. Postgrad. Med."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Costi, S., Germinario, S., Pandolfi, M., Pellico, M.R., Amati, A., Gattinara, M., Chighizola, C.B., Caporali, R., and Marino, A. (2023). Chronic Nonbacterial Osteomyelitis and Inflammatory Bowel Disease: A Literature Review-Based Cohort. Children, 10.","DOI":"10.3390\/children10030502"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1007\/s10067-025-07306-1","article-title":"Associated diseases and their effects on disease course in patients with chronic non-bacterial osteomyelitis: Retrospective experience from a single center","volume":"44","year":"2025","journal-title":"Clin. Rheumatol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1186\/s12969-022-00772-w","article-title":"Two phenotypes of chronic recurrent multifocal osteomyelitis with different patterns of bone involvement","volume":"20","author":"Wagenknecht","year":"2022","journal-title":"Pediatr. Rheumatol. Online J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12969-021-00657-4","article-title":"Clinical characteristics and outcomes of chronic nonbacterial osteomyelitis in children: A multicenter case series","volume":"20","author":"Ma","year":"2022","journal-title":"Pediatr. Rheumatol. Online J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1186\/s12969-022-00698-3","article-title":"Chronic nonbacterial osteomyelitis in children: A multicentre Belgian cohort of 30 children","volume":"20","author":"Kaut","year":"2022","journal-title":"Pediatr. Rheumatol. Online J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1186\/s13244-022-01288-3","article-title":"Chronic nonbacterial osteomyelitis: The role of whole-body MRI","volume":"13","author":"Nico","year":"2022","journal-title":"Insights Imaging"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1047","DOI":"10.1093\/mr\/roaf045","article-title":"The first nationwide epidemiological survey of chronic recurrent multifocal osteomyelitis in Japan","volume":"35","author":"Maeda","year":"2025","journal-title":"Mod. Rheumatol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1228","DOI":"10.1002\/acr.23462","article-title":"Consensus Treatment Plans for Chronic Nonbacterial Osteomyelitis Refractory to Nonsteroidal Antiinflammatory Drugs and\/or With Active Spinal Lesions","volume":"70","author":"Zhao","year":"2018","journal-title":"Arthritis Care Res."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/9\/1642\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T08:39:13Z","timestamp":1787819953000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/9\/1642"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,27]]},"references-count":27,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["medicina62091642"],"URL":"https:\/\/doi.org\/10.3390\/medicina62091642","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,27]]}}}