Nonbacterial Osteomyelitis Research Articles

Accuracy and Performance Characteristics of Administrative Codes for the Diagnosis of Autoinflammatory Syndromes

Objective The aim of this study was to evaluate and validate the accuracy and performance characteristics of administrative codes in diagnosing autoinflammatory syndromes (AISs). Methods We identified potential AIS patients from the electronic medical records at the University of Iowa Hospital and Clinics and the Stead Family Children's Hospital using a screening filter based on the 10th edition of the International Classification of Diseases (ICD-10) codes and interleukin-1 antagonists. Diagnostic criteria for adult-onset Still disease, systemic juvenile idiopathic arthritis, Behçet disease (BD), familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), and SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome and chronic nonbacterial osteomyelitis (SAPHO-CNO) were reviewed for each patient. Patients who did not meet the diagnostic criteria were categorized as non-AIS. In this cross-sectional study, we calculated the sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve for the ICD codes in diagnosing AIS. Results Out of the 502 patients with potential AIS, 338 patients (67%) had a true AIS diagnosis. Sensitivity ranged from 80% (SAPHO-CNO) to 100% (BD and FMF), and positive predictive value ranged from 15% (FMF) to 80% (SAPHO-CNO). Specificity ranged from 81% (FMF) to 99% (CAPS and SAPHO-CNO), whereas negative predictive value ranged from 98% (adult-onset Still disease) to 100% (systemic juvenile idiopathic arthritis, BD, FMF, and CAPS). All ICD codes or code combinations for the diagnosis of specific AIS subtypes showed high accuracy with areas under the receiver operating characteristic curve ≥0.89. Conclusions This study validated the accuracy of administrative codes for diagnosing AIS, supporting their use in constructing AIS cohorts for clinical outcomes research.

Chronic Non-bacterial Osteomyelitis (CNO) In Childhood: A Review.

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disorder mostly affecting children and adolescents. Although it is considered a rare disease, CNO is likely to be the single most common autoinflammatory bone disease in childhood, underdiagnosed and underreported due to a lack of awareness of the condition in both medics and patients and the absence of validated diagnostic criteria. The exact underlying pathogenesis of CNO remains unknown, making targeted treatment difficult. This issue is exacerbated by the lack of any randomised control trials, meaning that treatment strategies are based solely on retrospective reviews and case series. This review summarises the current concepts in pathophysiology, the clinical features that help differentiate important differential diagnoses, and an approach to investigating and managing children with CNO. Ultimately, the timely and thorough investigation of children and young people with CNO is vitally important to exclude important mimics and initiate appropriate management that can prevent the complications of persistent inflammatory bone disease.

Chronic nonbacterial osteomyelitis in neuroradiology - behavior and evolution of vertebral and mandibular lesions on imaging.

Chronic nonbacterial osteomyelitis (CNO) is a rare non-infectious inflammatory musculoskeletal disease where imaging plays a key diagnostic role. Vertebral and mandibular lesions are frequent manifestations, meaning their awareness is crucial for the neuroradiologist to avoid delays in diagnosis and treatment. Characterize vertebral and mandibular CNO lesions on imaging to assist practicing neuroradiologists in better identifying this disease. Retrospective review of all CNO patients of our pediatric center, including only patients with vertebral or mandibular lesions. All imaging exams were analyzed to record lesion characteristics. We included 13 patients (six male). The mean age of onset was 12.3years. Ten patients had only vertebral lesions, two had only mandibular lesions, and one had both. For patients with vertebral lesions, the median number of levels affected was three, 81.8% had multiple levels affected, 90.0% had dorsal spine lesions, 72.7% had platyspondyly, and 81.8% had inflammatory changes. All vertebral lesions had at least partial resolution of inflammatory findings, the mean time of lesion activity was 2.5years, and recurrence occurred in 27.3%. Three patients had sacral lesions, all with sacroiliitis. In patients with mandibular lesions, all had unilateral lesions involving the mandibular ramus, all had hyperostosis, periosteal reaction, bone edema, and soft tissue inflammation, all had partial resolution on follow-up, and one had recurrence. CNO vertebral lesions are not rare, are often multiple, predominantly affect dorsal levels, and most result in vertebral height loss. Resolution of vertebral inflammatory lesions is frequent, but so is recurrence. Sacral lesions may be present and result in sacroiliitis. The mandible may be a site of unifocal disease, typically affecting the ramus, with prominent bony changes and soft tissue inflammation.

Chronic Noninfectious Osteomyelitis: A Review of Imaging Findings

AbstractChronic noninfectious osteomyelitis or chronic nonbacterial osteomyelitis (CNO), also known as chronic recurrent multifocal osteomyelitis, is an autoinflammatory bone disorder primarily affecting the pediatric age group. Currently, it is diagnosed on the basis of clinical, laboratory, and imaging features. Imaging plays a crucial role in the diagnosis and follow-up of CNO with whole body magnetic resonance imaging (WBMRI) being the main modality. Radiographs assist in exclusion of common differential diagnoses like infections and malignancy. WBMRI aids in disease detection and exclusion of differential diagnoses, identifies additional lesions, and has a role in ascertaining the pattern of bony involvement which helps with prognostication and grading. Recent recognition of specific morphological and distribution patterns on WBMRI is increasingly allowing an upfront diagnosis of this entity to be made on imaging alone. It is also helpful for assessment of response to therapy during follow-up. This review aims to summarize the role of imaging in the evaluation of CNO, with special emphasis on WBMRI in its assessment.

An improved understanding of pediatric chronic nonbacterial osteomyelitis pathophysiology informs current and future treatment.

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease that primarily affects children and young people. It can cause significant pain, reduced function, bone swelling, and even (vertebral body) fractures. Because of a limited understanding of its pathophysiology, the treatment of CNO remains empiric and is based on relatively small case series, expert opinion, and personal experience. Several studies have linked pathological NOD-kike receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activation and the resulting imbalance between pro- and anti-inflammatory cytokine expression with CNO. This agrees with elevated pro-inflammatory (mostly) monocyte-derived protein signatures in the blood of CNO patients that may be used as future diagnostic and/or prognostic biomarkers. Recently, rare variants in the P2RX7 gene, encoding for an ATP-dependent transmembrane channel, were linked with increased NLRP3 inflammasome assembly and prolonged monocyte/macrophage survival in CNO. Although the exact molecular mechanisms remain unclear, this will inform future target-directed and individualized treatment. This manuscript reviews most recent developments and their impact on diagnostic and therapeutic strategies in CNO.

Diagnostic Value of Whole-Body MRI in Pediatric Patients with Suspected Rheumatic Diseases.

Background and Objectives: The diagnosis of rheumatic diseases in children is challenging and requires the use of advanced imaging examinations such as whole-body magnetic resonance imaging (MRI). Whole-body MRI allows visualization of bone marrow edema (BME), muscle edema, joint effusion and changes in the soft tissues surrounding the joints. The aim of this study was to collect and compare whole-body MRI findings, laboratory results and clinical manifestations of pediatric patients with suspected rheumatic disease. Materials and methods: In this retrospective single-center study, 33 patients who underwent whole-body MRI were included. Their age ranged from 9 to 17 years, and 24 (72.73%) of the patients were female. Patients were diagnosed as follows: juvenile idiopathic arthritis (27.27%), juvenile idiopathic inflammatory myopathies (21.21%), chronic nonbacterial osteomyelitis (21.21%) and other medical conditions (30.30%), such as arthritis associated with infection, scleroderma, Takayasu arteritis, polyarteritis nodosa and joint damage. Results: The most common symptom reported by 26 (79.79%) patients was pain. On physical examination, the limitation of joint mobility was examined in 17 (51.51%), swelling of the joints was observed in 12 (36.36%) patients and decreased muscle strength was noticed in 11 (33.33%) patients. An increase in the C-reactive protein (12%), erythrocyte sedimentation rate (9%), leukocyte count (9%) and creatine kinase (CK) (18%) was observed. Whole-body MRI revealed myositis (30%), joint effusion (27%) and BME (24%). The statistical analysis showed a significant relationship between myositis and the elevated CK level (p < 0.05). Conclusions: The most common symptom in the studied population was pain, while the limitation of joint mobility was found in more than half of patients. Myositis was the most commonly imaged lesion on the whole-body MRI and it was related to an increase in the CK level.

Utilization of Whole-Body Magnetic Resonance Imaging in Challenging Diagnoses in Pediatric Rheumatology.

The aim of this study was to investigate the use of whole-body magnetic resonance imaging (WBMRI) in cases where we suspected rheumatic disease in our pediatric rheumatology clinic. We conducted a retrospective analysis of demographic, clinical, laboratory, and imaging data pertaining to pediatric patients who presented at our clinic and underwent WBMRI over the last 5 years. Our investigation targeted children experiencing diffuse musculoskeletal pain, where precise localization was challenging and suspicion of rheumatological pathology persisted despite inconclusive results from conventional diagnostic modalities. A total of 87 patients (33 female) underwent WBMRI at our clinic, with a median age (minimum-maximum) of 11.3 (0.5-18) years. Whole-body magnetic resonance imaging was performed in 4 patients suspected with dermatomyositis (DM) where muscle biopsy was not feasible, revealing muscle involvement and myositis. Additionally, WBMRI was utilized in 4 patients diagnosed with chronic nonbacterial osteomyelitis (CNO) to assess recurrence, identifying new active lesions in 3 patients. Among the remaining 79 patients, 34 received a new diagnosis of CNO. Clinically, supported by additional findings in laboratory and WBMRI, 18 were diagnosed with juvenile idiopathic arthritis (JIA), 5 with protracted febrile myalgia syndrome (PFMS), 5 with acute osteomyelitis, and 1 with viral myositis. The results were normal for 17 patients. Most of the WBMRIs conducted at the clinic under study were primarily performed on patients suspected of having CNO. Additionally, WBMRI was found to be supportive and beneficial in cases of suspected DM, PFMS, and JIA during the diagnosis.

Radiographs in Pediatric Rheumatology: Where Do We Stand?

AbstractRheumatic disorders in children include inflammatory arthritis, inflammatory bone disorders such as chronic nonbacterial osteomyelitis (CNO), connective tissue disorders, and vasculitides (juvenile dermatomyositis, scleroderma). The diagnosis in these children is based on a combination of history, clinical examination, and laboratory investigations. Radiographs play an important role in children with arthritis, who have atypical presentation or for assessment of disease-related damage and differentiation from mimics. Further, radiographs also have an ancillary role in the assessment of musculoskeletal disorders such as dermatomyositis and hemophilia. This review seeks to present a detailed analysis of the specific indications and advantages of radiographs in the situations. Further, a structured reporting format for assessment of radiographs in pediatric rheumatic disorders has also been presented for the reader's reference.

Incidence of chronic recurrent multifocal osteomyelitis in children and adolescents in the UK and Republic of Ireland.

Chronic Recurrent Multifocal Osteomyelitis (CRMO), also known as chronic nonbacterial osteomyelitis (CNO), is a rare autoinflammatory condition affecting the bones in children and teenagers. The actual incidence of CRMO remains uncertain. The objective of this study is to identify the incidence of CRMO in children and young people under the age of 16 years in the United Kingdom (UK) and Republic of Ireland (ROI). We also aim to delineate the demographics, clinical presentation, investigations, initial management and healthcare needs for children and adolescents with CRMO. We conducted monthly surveys among all paediatric consultants and paediatric orthopaedic surgeons to identify patients newly diagnosed with CRMO between October 2020 and November 2022. A standardised questionnaire was sent to reporting clinicians to collect further information. Over the surveillance period, 288 patients were reported, among which, 165 confirmed and 20 probable cases were included in the analysis. The highest incidences were among 8-10 year-olds. A two-to-one female-to-male difference in incidence was observed, and male patients were more likely to present with multifocal disease. A negative correlation was observed between reporting clavicular and leg pain. Investigation-wise, 80.0% of patients were reported to have undergone whole-body MRI and 51.1% had bone biopsies. The most common initial treatments were NSAIDs (93.9%) and bisphosphonates (44.8%). This study estimates an average annual CRMO incidence of 0.65 cases per 100 000 children and adolescents in the UK and ROI. These findings establish a crucial baseline for ongoing research and improvement in the care of individuals with CRMO.

Simultaneous onset of chronic nonbacterial osteomyelitis in siblings.

Chronic nonbacterial osteomyelitis (CNO) is an uncommon autoinflammatory disorder. Significant effort has recently been spent to better define and treat this disorder including development of consensus treatment protocols, validate disease activity tools, and refining classification criteria. However, the underlying immunopathogenesis of the disease remains elusive. In this report, we describe the simultaneous onset of CNO in siblings. A pathogenic gene mutation was not identified, and these sisters lacked a similar biomarker profile. This report highlights that if a genetic predisposition for CNO exists, it may be related to complex polygenic or multifactorial mechanisms of disease evolution.

Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis, Palmoplantar Pustulosis, and Neutrophilic Dermatoses: A GRAPPA 2023 Annual Meeting Update.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and chronic nonbacterial osteomyelitis (CNO) are rare autoinflammatory/autoimmune conditions seen in adults and children. Although osteoarticular manifestations are the primary distinguishing features of SAPHO, over half of patients also have palmoplantar pustulosis (PPP). These and other associated disorders such as acne, inflammatory bowel disease, and hidradenitis suppurativa are characterized, at least in the early stages, by neutrophilic infiltration. The bone and skin manifestations exhibit both innate and adaptive immune responses and therefore share similar pathogenic molecules and overlapping treatment targets. At the Group for Research and Assessment for Psoriasis and Psoriatic Arthritis (GRAPPA) 2023 annual meeting, a 3-part presentation provided an overview of current efforts at establishing consensus on diagnosis/classification, treatment, and core outcome sets for SAPHO/CNO; an overview of PPP in SAPHO and as a standalone condition; and finally, an overview of the role of the neutrophil in these disorders.

TNF-alpha blockade in Primary Chronic Non-Bacterial Osteomyelitis of the Mandible.

Primary chronic Non-Bacterial Osteomyelitis of the jaw is a rare auto-inflammatory disease of unknown aetiology that bears pathophysiological resemblance to both the synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome in adults and chronic recurrent multifocal osteomyelitis (CRMO) in children. Both SAPHO and CRMO respond to TNF-alpha blockade. Previously reported treatment regimens in CNOM including non-steroidal anti-inflammatory drugs, corticosteroids, antibiotics, anti-resorptive therapy, and surgery all bear disappointing results. TNF- α blockade is suggested as a treatment option by some experts but this is not backed by any clinical data.We sought to retrospectively and exhaustively report our experience of anti-TNF alpha therapy in refractory CNOM. Fifteen patients with refractory CNOM and high disease burden were referred to our centre. TNF- α blockade was attempted in 10 cases, given its efficacy in neighbouring diseases, its good tolerance profile and failure of previous treatment strategiesWe herein retrospectively report detailed outcomes for all patients having received anti-TNF alpha therapy for this indication in our centre. TNF-α-targeting therapy resulted in a rapid and sustained remission in a majority of patients with CNOM, without serious adverse events. Treatment was tapered and stopped without relapse in some patients despite a refractory course of several years. Male sex seems to be associated with a poorer outcome. Our results suggest that blocking TNF-α is efficient and safe in CNOM.

Chronic recurrent multifocal osteomyelitis masquerading as multifocal bone Langerhans cell histiocytosis in children: A case series from a tertiary cancer center

Chronic recurrent multifocal osteomyelitis (CRMO), also known as chronic non-bacterial osteomyelitis (CNO), is an autoimmune inflammatory bone disorder mainly affecting children and adolescents. The clinical presentation varies from mild, self-limiting unifocal bone inflammation, which is more common, to multifocal recurrent disease. CRMO can be misdiagnosed as multifocal bone Langerhans cell histiocytosis (LCH), infections, lymphoma, or metabolic bone disease. Clinical features are highly variable and not very specific. Most children experience vague aches and pains over prolonged periods but remain generally well and do not exhibit growth failure. In this article, we describe a case series of three children who presented with multifocal bone disease and were initially referred for LCH; however, detailed investigations confirmed the diagnosis of CRMO. The treatment options included non-steroidal anti-inflammatory drugs, corticosteroids, and disease-modifying anti-rheumatic drugs. Other treatment options included anti-tumor necrosis factor agents and bisphosphonates, similar to those used for autoimmune bone diseases. CRMO should be considered a differential diagnosis in children presenting with chronic, vague, and recurrent bony symptoms with or without systemic symptoms.

РАЗВИТИЕ ХРОНИЧЕСКОГО МУЛЬТИОЧАГОВОГО НЕБАКТЕРИАЛЬНОГО ОСТЕОМИЕЛИТА У ПАЦИЕНТА С ИСХОДНО ДИАГНОСТИРОВАННЫМ СИСТЕМНЫМ ЮВЕНИЛЬНЫМ АРТРИТОМ: КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ

Systemic juvenile arthritis (sJA) is a special variant of chronic arthritis in children belonging to the spectrum of polygenic autoinflammatory diseases whose main features are persistent febrile fever, skin rashes, other systemic manifestations (serositis, lymphadenopathy, hepatosplenomegaly) as well as the presence of joint damage with the frequent development of destructive polyarthritis and osteonecrosis, high laboratory indicators of systemic inflammation either at the disease onset or delayed. The list of differentiated conditions includes many diseases such as infections, cancer, primary immunodeficiencies, monogenic autoinflammatory diseases etc. Authors represent a clinical case of a patient with sJA manifestations who was diagnosed with chronic multifocal nonbacterial osteomyelitis (CMNO), that demonstrates the great difficulties in diagnosis and the variability of the course of rheumatic diseases in childhood, which in its turn causes a delay in the timely prescription of effective therapy. Thus, patients with manifestations of a systemic inflammatory process, joint changes, especially those with an atypical course of the disease, pain in the bones and joints of a nocturnal nature, as well as an insufficient response to the therapy even long-term, are in need of conducting of a differential diagnostic search with the inclusion of CMNO, the ‘whole body’ mode magnetic-resonance tomography prescribed by a rheumatologist practitioner.

Characteristics of chronic non-bacterial osteomyelitis in children living in the Novosibirsk region

Characteristics of chronic non-bacterial osteomyelitis in children living in the Novosibirsk region

Chronic Nonbacterial Osteomyelitis, Hidradenitis Suppurativa, and SAPHO Syndrome

Introduction: Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome may represent one side of a spectrum of disease that also includes chronic nonbacterial osteomyelitis. Case: A 23-year-old male with bone pain in the anterior chest, shoulder, clavicles, left elbow, and left ankle presented to rheumatology clinic after multiple evaluations for infectious osteomyelitis. Imaging and deep bone biopsies of affected areas were consistent with chronic osteomyelitis, with labs notable for elevated erythrocyte sedimentation rate, C-reactive protein, and positivity for HLA-B27. A full skin exam was consistent with hidradenitis suppurativa, and he was started on infliximab and methotrexate with improvement in both his osteoarticular and skin symptoms. Conclusions: Patients presenting with features of follicular occlusion or neutrophilic dermatoses in conjunction with bone pain should be evaluated for SAPHO/CNO. In patients with SAPHO/CNO with vertebral involvement, bisphosphonates in addition to anti-inflammatory medications (such as methotrexate and TNF-inhibitors) can be effective.

Chronic secondary orofacial pain as the first symptom of chronic non-bacterial osteomyelitis in the mandible: a case report and literature review

Chronic non-bacterial osteomyelitis clinically manifests with pain, swelling and limitation of movement. When it affects the jaws, it can cause pain, similar to other orofacial conditions, requiring a correct differential diagnosis. The objective of this study was to report a clinical case of chronic secondary orofacial pain as the first manifestation of an inflammatory bone disease located in the mandible, in addition to discussing the diagnostic hypotheses, the pathophysiological aspects and the therapy. A 21-year-old male patient came to the service complaining of pain in the mandible, preauricular and temporal regions bilaterally with one year of evolution, associated with anterior open bite and psychological impairment. So, it was chronic orofacial pain secondary to non-bacterial osteomyelitis with a high rate of bone remodeling. Elevation of pro-inflammatory cytokines can lead to an increased power cycle of nociceptive signaling, chronic inflammation, and bone loss. Pro-inflammatory cytokines that originate in neuronal and glial cells can trigger effects such as chronic hyperexcitability, changes in the phenotypic expression of nociceptors and abnormal processing of noxious signals. The patient is still undergoing treatment and without pain. Careful assessment, ordering tests and multidisciplinary investigation are essential in the care of patients with chronic and complex orofacial pain.

Chronic non-bacterial osteomyelitis (CNO) and chronic recurrent multifocal osteomyelitis (CRMO) with a focus on pamidronate therapy.

Chronic recurrent multifocal osteomyelitis (CRMO), also called chronic nonbacterial osteomyelitis (CNO) or nonbacterial osteomyelitis (NBO), is a rare autoinflammatory bone disease of unknown etiology. However, the number of patients properly diagnosed would increase with better knowledge of the disease. In this regard, whole-body magnetic resonance imaging (WB MRI) has been found to be a better predictor of active lesions than clinical examination. Importantly, the RINBO index (radiologic index for NBO) quantifies the involvement based on the WB MRI. Further, a chronic nonbacterial osteomyelitis MRI scoring (CROMRIS) has been developed as an online tool for assessing WB MRI. The therapy consists of non-steroidal anti-inflammatory drugs (NSAIDs), bisphosphonates (pamidronate, zoledronate, etc.) and other drugs, including biologics. Pamidronate is an appropriate and safe therapy. The first pilot prospective randomised controlled trial (RCT) on pamidronate vs. placebo was carried out in adults. No RCT has been done in children yet. Besides RCTs, there are a number of issues to be explored in future, i.e. predictors of therapy effect, optimal therapy duration, predictors of therapy discontinuation and evaluation of optimal therapy protocol. Recently, the CNO clinical disease activity score (CDAS) was constructed and validated but the classification criteria are still being developed. As collaboration on this rare disease is essential, a prospective Chronic Nonbacterial Osteomyelitis International Registry (CHOIR) was established to generate future comparative effectiveness research data.

P019 Comparison of newly proposed chronic nonbacterial osteomyelitis classification criteria to previous diagnostic criteria

Abstract Background/Aims Chronic nonbacterial osteomyelitis (CNO) is an aseptic autoinflammatory bone disease of unknown etiology. This diagnosis can be delayed due to the non-specific nature of symptoms and normal imaging studies. New classification criteria were proposed in 2022. This study seeks to validate these new classification criteria by comparing them to previous diagnostic criteria in a cohort of known CNO patients. Methods This is a retrospective case-series of pediatric patients diagnosed with CNO (n = 39) between 2012 and 2023 in Virginia, USA. The newly proposed classification criteria (Table 1) was applied to this cohort. The entry criteria of chronic bone pain, age &amp;lt;18 years, abnormal radiograph and/or MRI were used prior to applying the newly proposed classification criteria. The 2008 Jansson diagnostic criteria and 2016 Bristol diagnostic criteria were also applied to the cohort for comparison and further validation. The clinical manifestations, laboratory results, and imaging studies that lead to a diagnosis of CNO were reviewed. Results The average age of diagnosis was 10 (range 2-17) years-old with the average time between onset of symptoms to confirmed clinical diagnosis being 24 (range 1-120) months. The most common presenting symptoms were bone pain (100%) and arthritis (49%). Evidence of radiographic abnormalities leading to CNO diagnosis was found with regional MRI (64%), bone scan (44%) with some requiring full body MRI (31%). Only one patient did not meet the new classification criteria (1/39; 3%) because of age &amp;lt;3 years, fever and elevated ESR which together gave less than the required 55 points for criteria fulfillment. One different patient (1/39; 3%) did not meet both the Bristol and Jansson criteria because of unifocal disease and lack of bone biopsy. Conclusion This retrospective chart review validates the newly proposed classification criteria for CNO. Older diagnostic criteria (Jansson and Bristol) both require advanced imaging and at times bone biopsy for fulfillment. We conclude that the newly proposed criteria is easy to apply even in the absence of a bone biopsy or advanced imaging studies. The newly proposed criteria will aid in the development of a homogeneous cohort for future studies about CNO. Disclosure A.M. Patel: Member of speakers’ bureau; ABBVIE, AMGEN, SANOFI. K.S. Lee: None. A.J. Kim: None.

Arthritis and osteomyelitis in childhood and adolescence-Bacterial and nonbacterial

Bacterial arthritis and osteomyelitis are usually acute diseases, which in this way differ from the often insidious course of nonbacterial osteomyelitis; however, there is often an overlap both in less acute courses of bacterial illnesses and also in nonbacterial osteitis. The overlapping clinical phenomena can be explained by similar pathophysiological processes. In bacteria-related illnesses the identification of the pathogen and empirical or targeted anti-infectious treatment are prioritized, whereas no triggering agent is known for nonbacterial diseases. The diagnostics are based on the exclusion of differential diagnoses, clinical scores and magnetic resonance imaging (MRI). An activity-adapted anti-inflammatory treatment is indicated.