You are in: eMedicine Specialties > Radiology > PEDIATRICS Juvenile Rheumatoid ArthritisArticle Last Updated: May 9, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Ali Hekmatnia, MD, Associate Professor, Department of Pediatric Radiology, Isfahan University of Medical Sciences, Iran; Consulting Staff, Department of Radiology, Al-Zahra Hospital, Iran Coauthor(s): Kieran McHugh, MBBCh, Honorary Lecturer, The Institute of Child Health; Consultant Pediatric Radiologist, Department of Radiology, Great Ormond Street Hospital for Children, London, UK; Reza Basiratnia, MD, Assistant Professor, Department of Radiology, Isfahan University of Medical Sciences, Iran; Amaka C Offiah, BSc, MBBS, MRCP, FRCR, PhD, Consultant Academic Pediatric Radiologist, Department of Pediatric Radiology, Great Ormond Street Hospital for Children, UK Editors: Fredric A Hoffer, MD, FAAP, FSIR, Professor of Radiology, University of Washington; Section Chief of Interventional Radiology, Department of Radiology, Seattle Children's Hospital and Regional Medical Center; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; David A Stringer, MBBS, FRCR, Clinical Professor, National University of Singapore; Clinical Director, Diagnostic Imaging, National University Hospital; Head, Diagnostic Imaging, KK Women's and Children's Hospital, Singapore; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; Felix S Chew, MD, MBA, EdM, Professor, Department of Radiology, Vice Chairman for Radiology Informatics, Section Head of Musculoskeletal Radiology, University of Washington Author and Editor Disclosure Synonyms and related keywords: juvenile idiopathic arthritis, JIA, juvenile chronic arthritis, JCA, juvenile rheumatoid arthritis, JRA, rheumatoid factor, RF INTRODUCTIONSection 2 of 11
  BackgroundJuvenile idiopathic arthritis (JIA) is the most common chronic arthritis of children. It is one of the most common chronic illnesses of childhood and a major cause of short- and long-term functional disability and eye disease leading to blindness. JIA is the term used throughout this article in preference to juvenile rheumatoid arthritis (JRA). Although it has been customary to refer to JIA as 1 disease, it is almost certainly 3 or more diseases, which may have the same cause, different causes, or a closely related series of host responses. The course of JIA is unpredictable. The course tends to be most predictable after the pattern of the disease is established. In 1864, Cornil first suggested the idea that inflammatory polyarthritis can occur in childhood, describing a 29-year-old woman who had had chronic inflammatory arthritis since the age of 12 years. In 1890, Diamant-Berger commented on the acute onset of disease, the predominant involvement of large joints, a course characterized by exacerbation and remission, the frequent disturbances of normal growth, and the generally good prognosis. Three sets of criteria are used to classify JIA: those developed by the American College of Radiology (ACR), those of the European League against Rheumatism (EULAR), and those proposed by the International League of Associations for Rheumatology (ILAR). The ACR criteria define arthritis, the age limit (<16 y), and the duration of disease (>6 mo) necessary for a diagnosis. They also recognize 3 types of onset: polyarticular, pauciarticular, and systemic. The EULAR proposed the term juvenile chronic arthritis (JCA) for the heterogeneous group of disorders that manifest as juvenile arthritis. The diagnosis requires that the arthritis begins before the age of 16 years, that it lasts for at least 6 weeks, and that other diseases are excluded. The ILAR criteria are currently the preferred classification system. The aim is to provide a unified classification system. The ILAR classification of JIA includes the following features:
PathophysiologyThe etiology and pathogenesis of JIA are unclear despite numerous investigations. JIA may represent not a single disease but a syndrome of diverse causes. Both abnormal immune regulation and cytokine production may play a role. Levels of circulating immune complexes in JIA have parallel activity with disease and systemic features. JIA is most assuredly a complex genetic trait. The various forms of JIA have nonmendelian inheritance, and interactions of several genes are likely important in these diseases. Arthritis is associated with the clinical course of many viral diseases, such as rubella, parvovirus B19, and influenza A. FrequencyUnited StatesDepending on location of the study and criteria, the prevalence is 86.1-94 cases per 100,000 population, and the incidence is 11.7 cases per 100,000 population per year. InternationalJIA is more common in Norway and Australia than in other countries. In Norway, the prevalence is 148.1 cases per 100,000 population, and the incidence is 22.6 cases per 100,000 population. Mortality/MorbidityThe disease-associated mortality is difficult to quantify, but it is estimated to be less than 1% in Europe and less than 0.5% in North America. Most deaths associated with JIA in Europe are related to amyloidosis, and most in the United States are related to infections.
Race
SexTwice as many girls as boys develop JIA.
AgeAlthough JIA is defined as arthritis beginning before age 16 years, the age at onset is often young, with the highest frequency in children aged 1-3 years.
Clinical DetailsComplications Complications in JIA can be divided into skeletal and extraskeletal. Skeletal complications include the following:
Extraskeletal complications include the following:
History Pertinent historical features are listed below.
DIFFERENTIALSSection 3 of 11
Caffey Disease Eosinophilic Granuloma, Skeletal Osteoarthritis, Primary Osteomyelitis, Acute Pyogenic Osteomyelitis, Chronic Osteoporosis, Involutional Pigmented Villonodular Synovitis Spondylodiskitis RADIOGRAPHSection 4 of 11
FindingsPlain radiography is the primary method of imaging for the diagnosis and follow-up evaluation of JIA. Basic radiographic changes include the following:
Degree of ConfidenceThe main limitation of conventional radiography is that it does not allow direct examination of the articular cartilage, synovium, and other important noncalcified structures in a joint. CT SCANSection 5 of 11
FindingsCT scanning is the best method for analyzing some regions with complex anatomy, such as the sacroiliac joint and occasionally the hip, shoulder, or temporomandibular joints. Degree of ConfidenceMRI has now largely superseded CT in the overall assessment of JIA. The major disadvantage of CT scanning is that it involves a substantial radiation dose. MRISection 6 of 11
FindingsMRI provides the most sensitive radiologic indicator of disease activity. MRI can depict synovial hypertrophy, define soft tissue swelling, and demonstrate excellent detail of the status of articular cartilage and overall joint integrity. To improve visualization of synovial hypertrophy and improve detection of cartilaginous erosions when an inflammatory arthritis is suspected, contrast-enhanced sequences should be performed. Synovitis and a joint effusion may have similar hyperintensity on T2-weighted (T2W) and short-tau inversion recovery (STIR) images. Therefore, gadolinium-enhanced T1-weighted (T1W) MRIs are necessary to accurately define active synovitis (see Image 4). Gadolinium-based contrast agents (gadopentetate dimeglumine [Magnevist], gadobenate dimeglumine [MultiHance], gadodiamide [Omniscan], gadoversetamide [OptiMARK], gadoteridol [ProHance]) have recently been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). For more information, see the eMedicine topic, Nephrogenic Fibrosing Dermopathy. The disease has occurred in patients with moderate to end-stage renal disease after being given a gadolinium-based contrast agent to enhance MRI or MRA scans. As of late December 2006, the FDA had received reports of 90 such cases. Worldwide, over 200 cases have been reported, according to the FDA. NSF/NFD is a debilitating and sometimes fatal disease.Characteristics include red or dark patches on the skin; burning, itching, swelling, hardening, and tightening of the skin; yellow spots on the whites of the eyes; joint stiffness with troublemoving or straightening the arms, hands, legs, or feet; pain deep in the hip bones or ribs; and muscle weakness. For more information, see the FDA Public Health Advisory or Medscape. ULTRASOUNDSection 7 of 11
FindingsSome enthusiasts claim that ultrasonography is more sensitive than plain radiography in the detection of cartilage erosions and effusions, but ultrasonography is notoriously operator dependent. On sonograms, inflamed synovium can appear as an area of mixed echogenicity lining the articular cartilage. Serial measurements of synovial thickness and effusion volumes have been used to monitor disease progression. The vascularity of the synovium can be assessed with Doppler flow studies. NUCLEAR MEDICINESection 8 of 11
FindingsThe major application of bone scintigraphy in people with JIA is in determining the distribution of disease. The major disadvantage of bone scintigraphy is its substantial radiation dose. Degree of ConfidenceBone scanning remains an effective method with high sensitivity and low specificity. Bone scanning may be combined with single photon emission CT (SPECT) to increase sensitivity in the 1 or more foci of abnormal isotopic accumulation. INTERVENTIONSection 9 of 11
Medical/Legal Pitfalls
Special Concerns
MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
Juvenile Rheumatoid Arthritis excerpt Article Last Updated: May 9, 2007 | ||||||||||||||||||||||||||||
