Eva Kirkhus

Incidence and characteristics of arthritis in Norwegian children: a population-based study.

OBJECTIVE. The purpose of this work was to assess the annual incidence of arthritis in children and describe early disease and patient characteristics, microbiologic features, and immunogenetic factors in children with different subgroups of childhood arthritis. PATIENTS AND METHODS. A population-based multicenter study was performed in southeastern Norway between June 1, 2004, and May 31, 2005. The total population of children under 16 years of age was 255303. Physicians were asked to refer their patients with suspected arthritis to the local department of pediatrics or rheumatology. The children were assessed on the basis of clinical, radiologic, and laboratory examinations at inclusion and followed up at 6 weeks, 6 months, and thereafter as long as clinically indicated. A chart review was performed to identify patients with arthritis who had not been included prospectively. RESULTS. The total annual incidence of arthritis was 71 per 100000 children. Transient arthritis, juvenile idiopathic arthritis, postinfectious arthritis, and infectious arthritis were found in 43, 14, 9, and 5 of 100000 children, respectively. The incidence was higher in children under the age of 8 years than in older children (107 vs 34 per 100000). Arthritis occurred more frequently in boys than in girls before the age of 8 years but not thereafter. The median age of onset was lower in children with infectious arthritis than in those with other types of arthritis. Monarthritis was less frequent in patients with juvenile idiopathic arthritis than in the other subgroups (64% vs 83%–100%). Ten percent of the patients had poststreptococcal reactive arthritis, and only 1 had enteropathic arthritis. Autoantibodies and the presence of HLA-B27 were associated with juvenile idiopathic arthritis. CONCLUSIONS. The annual incidence of childhood arthritis was 71 per 100000 children. We found several factors that may help in differentiating between subgroups of arthritis.

Childhood osteomyelitis-incidence and differentiation from other acute onset musculoskeletal features in a population-based study

BackgroundOsteomyelitis can be difficult to diagnose and there has previously not been a prospective approach to identify all children in a defined geographic area. The aim of this study was to assess the annual incidence of osteomyelitis in children, describe the patient and disease characteristics in those with acute (< 14 days disease duration) and subacute osteomyelitis (≥ 14 days disease duration), and differentiate osteomyelitis patients from those with other acute onset musculoskeletal features.MethodsIn a population-based Norwegian study physicians were asked to refer all children with suspected osteomyelitis. Children with osteomyelitis received follow-up at six weeks, six months and thereafter as long as clinically needed.ResultsThe total annual incidence rate of osteomyelitis was 13 per 100 000 (acute osteomyelitis 8 and subacute osteomyelitis 5 per 100 000). The incidence was higher in patients under the age of 3 than in older children (OR 2.9, 95%: CI 2.3–3.7). The incidence of non-vertebral osteomyelitis was higher than the incidence of vertebral osteomyelitis (10 vs. 3 per 100 000; p = .002). Vertebral osteomyelitis was more frequent in girls than in boys (OR 7.0, 95%: CI 3.3–14.7). ESR ≥ 40 mm/hr had the highest positive predictive laboratory value to identify osteomyelitis patients at 26% and MRI had a positive predictive value of 85%. Long-bone infection was found in 16 (43%) patients. ESR, CRP, white blood cell count, neutrophils and platelet count were higher for patients with acute osteomyelitis than for patients with subacute osteomyelitis. Subacute findings on MRI and doctors delay were more common in subacute osteomyelitis than in acute osteomyelitis patients. Blood culture was positive in 26% of the acute osteomyelitis patients and was negative in all the subacute osteomyelitis patients.ConclusionThe annual incidence of osteomyelitis in Norway remains high. ESR values and MRI scan may help to identify osteomyelitis patients and differentiate acute and subacute osteomyelitis.

Long-term muscular outcome and predisposing and prognostic factors in juvenile dermatomyositis: A case–control study

To compare muscle strength, physical health, and HLA–DRB1 allele carriage frequencies in patients with longstanding juvenile dermatomyositis (DM) with that of controls, and to determine the presence of and risk factors for muscle weakness and magnetic resonance imaging (MRI)–detected muscle damage in juvenile DM patients.

Contrast-Enhanced Dynamic Magnetic Resonance Imaging of Finger Joints in Osteoarthritis and Rheumatoid Arthritis: An Analysis Based on Pharmacokinetic Modeling

Purpose: To investigate a two-compartment kinetic model applied to the dynamic time course of contrast enhancement as a method to differentiate between finger-joint synovitis in established osteoarthritis (OA) and rheumatoid arthritis (RA). Material and Methods: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of one hand in 19 patients and six healthy volunteers was undertaken. Eight patients had OA of the hand and eleven patients had RA. From the signal intensity curves, the three parameters Kps (endothelial transfer constant), Kep (elimination rate constant from extracellular space back to plasma) and Kel (elimination rate constant from plasma by renal excretion) were calculated. Results: The rate constant Kps showed the best separation between the groups with significantly higher values in the RA group compared to the OA group (P<0.005) and in the OA group compared to the control group (P<0.005). Significantly higher values of Kep were also found in the RA group compared with the OA group (P<0.005). Conclusion: DCE-MRI may provide useful information that can help differentiate synovitis in OA from synovitis in RA.

Differences in MRI findings between subgroups of recent-onset childhood arthritis.

BackgroundMRI is sensitive for joint inflammation, but its ability to separate subgroups of arthritis in children has been questioned. Infectious arthritis (IA), postinfectious arthritis (PA), transient arthritis (TA) and juvenile idiopathic arthritis (JIA) are subgroups that may need early, different treatment.ObjectiveTo determine whether MRI findings differ in IA, PA/TA and JIA in recent-onset childhood arthritis.Materials and methodsFifty-nine children from a prospective study of incidence of arthritis (n = 216) were, based on clinical and biochemical criteria, examined by MRI. Joint fluid, synovium, bone marrow, soft tissue and cartilage were scored retrospectively and analysed by Pearson chi-square test and logistic regression analysis.ResultsFifty-nine children had MRI of one station. IA was suggested by bone marrow oedema (OR 7.46, P = 0.011) and absence of T1-weighted and T2-weighted low signal intensity synovial tissue (OR 0.06, P = 0.015). Furthermore, soft-tissue oedema and reduced contrast enhancement in the epiphyses were more frequent in children with IA. JIA correlated positively with low signal intensity synovial tissue (OR 13.30, P < 0.001) and negatively with soft-tissue oedema (OR 0.20, P = 0.018). No significant positive determinants were found for PA/TA, but bone marrow oedema, soft-tissue oedema, irregular thickened synovium and low signal intensity synovial tissue was less frequent than in IA/JIA.ConclusionIn children with high clinical suspicion of recent onset arthritis, there was a significant difference in the distribution of specific MRI features among the diagnostic groups.

CT of the hips in the investigation of protrusio acetabuli in Marfan syndrome. A case control study

ObjectivesTo establish the prevalence of protrusio acetabuli (PA) in adults fulfilling the Ghent criteria for Marfan syndrome (MFS), and in a normal adult population.Methods105 adults with probable MFS and 107 controls were included. CT of the hips was obtained. A qualitative assessment of PA was performed. A new method for estimating the degree of PA was introduced with measurement of the parameter CWD (circle-wall distance). Results were compared to an alternative method based on MRI [1].Results87 of the study group fulfilled the Ghent criteria of MFS (Ghent positives), and 18 did not (Ghent negatives). PA was diagnosed qualitatively in 74.7% of Ghent positive persons, in 27.8% of Ghent negative persons, and in 3.7% of the controls. CWD was significantly different between the three groups (p < 0.001). A slight but significant gender difference was found in Ghent positive persons only. The alternative method did not differentiate between the groups with respect to PA, but showed a significant difference between genders.ConclusionsPA was found significantly more often in MFS persons than in controls. Our method was found to be robust and highly reproducible, giving a direct measurement of pelvic protrusion irrespective of pelvic shape.

Submaximal Exercise Capacity in Juvenile Dermatomyositis after Longterm Disease: The Contribution of Muscle, Lung, and Heart Involvement

Objective. To compare submaximal exercise capacity in patients with juvenile dermatomyositis (JDM) with controls, and analyze contributions of muscle, heart, and lung impairment in patients. Methods. Fifty-nine patients with JDM, with a mean 16.9 years after symptom onset, and 59 sex- and age-matched controls completed a 6-min walk test (6MWT) and a timed up and go (TUG) test. Muscle function, disease activity/damage, and health-related quality of life (HRQOL) were assessed by validated tools; heart function by echocardiography and electrocardiography; and lung function by spirometry, DLCO, and body plethysmography. A thoracic high-resolution computed tomography (HRCT) scan and magnetic resonance imaging of the thighs were completed in patients. Results. The 6MWT distance (6MWD) was 592 ± 81 m in patients versus 649 ± 79 m in controls (p < 0.001), and 563 ± 75 m in active versus 622 ± 76 m in inactive JDM (p = 0.004). The TUG time was 13.1 ± 2.1 s in patients versus 12.3 ± 2.0 s in controls (p = 0.034), and 13.7 ± 2.2 s in active versus 12.5 ± 1.8 s in inactive JDM (p = 0.028). No statistically significant difference was found between inactive JDM and controls in either test. In patients, the Childhood Myositis Assessment Score influenced the 6MWD and TUG time the most, followed by a low DLCO and HRCT pathology in the 6MWT and forced vital capacity in the TUG test. Medical Outcomes Study Short Form-36 physical component summary correlated strongly with both tests. Conclusion. Submaximal exercise capacity was reduced in patients with JDM, particularly those with active disease. This reduction was associated with muscle and lung dysfunction and poorer HRQOL.

A man in his forties with swelling in both orbits

UNLABELLED Erdheim-Chester disease. A multi-disiplinary challenge. The histiocytoses are a diverse, but rare group of disorders with symptoms affecting many organs, varying from self-limiting, localised lesions to disseminated multi-organ disease. The diagnostic challenges are illustrated and discussed in the following case. CASE REPORT A man in his forties was admitted to hospital due to pain in his right eye and visual disturbances. MRI imaging detected a mass in his right orbit and a minor mass in his left orbit. The histological results of the mass in his right orbit revealed an inflammatory process with lymphocytes and macrophages and no sign of vasculitis, infection or malignancy. The diagnosis pseudotumor orbita was made and treatment with corticosteroids was initiated. He did not respond to corticosteroids or radiotherapy and increasing symptoms necessitated rehospitalisation. Further tests disclosed a multisystem disease which affected the aorta, skeleton, lung, heart and kidney. The biopsy was reconsidered and the disease was classified as a histiocytosis with CD68 positive and CD1a negative cells. The diagnosis Erdheim-Chester was given, about 14 months after the initial hospitalisation. Treatment with interferon α was started.

Imaging of temporomandibular joint abnormalities in juvenile idiopathic arthritis with a focus on developing a magnetic resonance imaging protocol

Inflammation and damage in the temporomandibular joint (TMJ) often develop without clinical symptoms but can lead to severe facial growth abnormalities and impaired health-related quality of life, making early diagnosis of TMJ changes crucial to identify. Inflammatory and osteochondral changes detectable through magnetic resonance imaging (MRI) occur in TMJs of approximately 40% of children with juvenile idiopathic arthritis (JIA), and no other imaging modality or physical method of examination can reliably detect these changes. Therefore contrast-enhanced MRI is the diagnostic standard for diagnosis and interval monitoring of JIA. However the specific usage of MRI for TMJ arthritis is not standardized at present. There is a recognized need for a consensus effort toward standardization of an imaging protocol with required and optional sequences to improve detection of pathological changes and shorten study time. Such a consensus imaging protocol is important for providing maximum information with minimally necessary sequences in a way that allows inter-site comparison of results of clinical trials and improved clinical management. In this paper we describe the challenges of TMJ imaging and present expert-panel consensus suggestions for a standardized TMJ MRI protocol.