Juvenile dermatomyositis and polymyositis: Epidemiology, pathogenesis, and clinical manifestations
- Clare Hutchinson, MDCM, FRCPC
Clare Hutchinson, MDCM, FRCPC
- Pediatric Rheumatologist
- University of Toronto
- Brian M Feldman, MD, MSc, FRCPC
Brian M Feldman, MD, MSc, FRCPC
- Professor of Pediatrics
- University of Toronto
- Section Editors
- Thomas JA Lehman, MD
Thomas JA Lehman, MD
- Section Editor — Pediatric Rheumatology
- Professor of Clinical Pediatrics
- Cornell University Medical College
- Marc C Patterson, MD, FRACP
Marc C Patterson, MD, FRACP
- Section Editor — Pediatric Neurology
- Professor of Neurology, Pediatrics, and Medical Genetics
- Chair, Division of Child and Adolescent Neurology
- Mayo Clinic College of Medicine
Juvenile dermatomyositis (JDM) and juvenile polymyositis (JPM) are rare autoimmune myopathies in childhood. JDM is primarily a capillary vasculopathy, whereas JPM involves direct T cell invasion of muscle fibers similar to that seen in adult polymyositis (PM) [1,2]. However, as the diagnostic tools become more sophisticated (eg, biopsies that demonstrate inclusion body myositis or inflammatory dystrophies, or autoantibodies that are markers of particular types of myositis such as anti-signal recognition particle [SRP] and necrotizing myopathy), fewer patients are diagnosed with JPM, calling into question whether JPM is a specific entity. (See "Clinical manifestations of dermatomyositis and polymyositis in adults".)
The epidemiology, pathogenesis, and clinical manifestations of JDM and JPM are reviewed here. Diagnosis and treatment of these disorders are discussed elsewhere. (See "Juvenile dermatomyositis and polymyositis: Diagnosis" and "Juvenile dermatomyositis and polymyositis: Treatment, complications, and prognosis".)
JDM is the most common idiopathic inflammatory myopathy of childhood, accounting for approximately 85 percent of cases [3,4]. In population-based studies, JDM has a reported annual incidence that ranges from two to four cases per one million children [5-9]. The peak incidence is from 5 to 10 years of age [8,9]. Girls are affected more often than boys, with a two- to fivefold greater rate [7,8,10].
JPM occurs less frequently and accounts for only 3 to 6 percent of childhood idiopathic inflammatory myopathies [3,7].
Although the etiology remains unclear, it has been proposed that JDM and JPM are caused by an autoimmune reaction in genetically susceptible individuals, possibly in response to infection or environmental triggers such as prenatal exposure to tobacco smoke and particulate inhalants .
- Arahata K, Engel AG. Monoclonal antibody analysis of mononuclear cells in myopathies. I: Quantitation of subsets according to diagnosis and sites of accumulation and demonstration and counts of muscle fibers invaded by T cells. Ann Neurol 1984; 16:193.
- Banker BQ, Victor M. Dermatomyositis (systemic angiopathy) of childhood. Medicine (Baltimore) 1966; 45:261.
- McCann LJ, Juggins AD, Maillard SM, et al. The Juvenile Dermatomyositis National Registry and Repository (UK and Ireland)--clinical characteristics of children recruited within the first 5 yr. Rheumatology (Oxford) 2006; 45:1255.
- Ramanan AV, Feldman BM. Clinical features and outcomes of juvenile dermatomyositis and other childhood onset myositis syndromes. Rheum Dis Clin North Am 2002; 28:833.
- Oddis CV, Conte CG, Steen VD, Medsger TA Jr. Incidence of polymyositis-dermatomyositis: a 20-year study of hospital diagnosed cases in Allegheny County, PA 1963-1982. J Rheumatol 1990; 17:1329.
- Pelkonen PM, Jalanko HJ, Lantto RK, et al. Incidence of systemic connective tissue diseases in children: a nationwide prospective study in Finland. J Rheumatol 1994; 21:2143.
- Symmons DP, Sills JA, Davis SM. The incidence of juvenile dermatomyositis: results from a nation-wide study. Br J Rheumatol 1995; 34:732.
- Mendez EP, Lipton R, Ramsey-Goldman R, et al. US incidence of juvenile dermatomyositis, 1995-1998: results from the National Institute of Arthritis and Musculoskeletal and Skin Diseases Registry. Arthritis Rheum 2003; 49:300.
- Gardner-Medwin JM, Dolezalova P, Cummins C, Southwood TR. Incidence of Henoch-Schönlein purpura, Kawasaki disease, and rare vasculitides in children of different ethnic origins. Lancet 2002; 360:1197.
- Pachman LM, Abbott K, Sinacore JM, et al. Duration of illness is an important variable for untreated children with juvenile dermatomyositis. J Pediatr 2006; 148:247.
- Orione MA, Silva CA, Sallum AM, et al. Risk factors for juvenile dermatomyositis: exposure to tobacco and air pollutants during pregnancy. Arthritis Care Res (Hoboken) 2014; 66:1571.
- Harati Y, Niakan E, Bergman EW. Childhood dermatomyositis in monozygotic twins. Neurology 1986; 36:721.
- LEONHARDT T. Familial occurrence of collagen diseases. II. Progressive systemic sclerosis and dermatomyositis. Acta Med Scand 1961; 169:735.
- Mamyrova G, O'Hanlon TP, Monroe JB, et al. Immunogenetic risk and protective factors for juvenile dermatomyositis in Caucasians. Arthritis Rheum 2006; 54:3979.
- Pachman LM, Jonasson O, Cannon RA, Friedman JM. Increased frequency of HLA-B8 in juvenile dermatomyositis. Lancet 1977; 2:1238.
- Reed AM, Pachman LM, Hayford J, Ober C. Immunogenetic studies in families of children with juvenile dermatomyositis. J Rheumatol 1998; 25:1000.
- Vavrincová P, Havelka S, Cerna M, Stastny P. HLA class II alleles in juvenile dermatomyositis. J Rheumatol Suppl 1993; 37:17.
- Pachman LM, Liotta-Davis MR, Hong DK, et al. TNFalpha-308A allele in juvenile dermatomyositis: association with increased production of tumor necrosis factor alpha, disease duration, and pathologic calcifications. Arthritis Rheum 2000; 43:2368.
- Rider LG, Artlett CM, Foster CB, et al. Polymorphisms in the IL-1 receptor antagonist gene VNTR are possible risk factors for juvenile idiopathic inflammatory myopathies. Clin Exp Immunol 2000; 121:47.
- Mamyrova G, O'Hanlon TP, Sillers L, et al. Cytokine gene polymorphisms as risk and severity factors for juvenile dermatomyositis. Arthritis Rheum 2008; 58:3941.
- Niewold TB, Wu SC, Smith M, et al. Familial aggregation of autoimmune disease in juvenile dermatomyositis. Pediatrics 2011; 127:e1239.
- Massa M, Costouros N, Mazzoli F, et al. Self epitopes shared between human skeletal myosin and Streptococcus pyogenes M5 protein are targets of immune responses in active juvenile dermatomyositis. Arthritis Rheum 2002; 46:3015.
- Shrestha S, Wershil B, Sarwark JF, et al. Lesional and nonlesional skin from patients with untreated juvenile dermatomyositis displays increased numbers of mast cells and mature plasmacytoid dendritic cells. Arthritis Rheum 2010; 62:2813.
- Pachman LM. Inflammatory myopathy in children. Rheum Dis Clin North Am 1994; 20:919.
- Rider LG, Miller FW, Targoff IN, et al. A broadened spectrum of juvenile myositis. Myositis-specific autoantibodies in children. Arthritis Rheum 1994; 37:1534.
- Feldman BM, Reichlin M, Laxer RM, et al. Clinical significance of specific autoantibodies in juvenile dermatomyositis. J Rheumatol 1996; 23:1794.
- Gunawardena H, Wedderburn LR, North J, et al. Clinical associations of autoantibodies to a p155/140 kDa doublet protein in juvenile dermatomyositis. Rheumatology (Oxford) 2008; 47:324.
- Kobayashi I, Okura Y, Yamada M, et al. Anti-melanoma differentiation-associated gene 5 antibody is a diagnostic and predictive marker for interstitial lung diseases associated with juvenile dermatomyositis. J Pediatr 2011; 158:675.
- Artlett CM, Ramos R, Jiminez SA, et al. Chimeric cells of maternal origin in juvenile idiopathic inflammatory myopathies. Childhood Myositis Heterogeneity Collaborative Group. Lancet 2000; 356:2155.
- Reed AM, Picornell YJ, Harwood A, Kredich DW. Chimerism in children with juvenile dermatomyositis. Lancet 2000; 356:2156.
- Elst EF, Klein M, de Jager W, et al. Hsp60 in inflamed muscle tissue is the target of regulatory autoreactive T cells in patients with juvenile dermatomyositis. Arthritis Rheum 2008; 58:547.
- Christensen ML, Pachman LM, Schneiderman R, et al. Prevalence of Coxsackie B virus antibodies in patients with juvenile dermatomyositis. Arthritis Rheum 1986; 29:1365.
- Tang TT, Sedmak GV, Siegesmund KA, McCreadie SR. Chronic myopathy associated with coxsackievirus type A9. A combined electron microscopical and viral isolation study. N Engl J Med 1975; 292:608.
- Webster AD, Tripp JH, Hayward AR, et al. Echovirus encephalitis and myositis in primary immunoglobulin deficiency. Arch Dis Child 1978; 53:33.
- Pachman LM, Hayford JR, Hochberg MC. Seasonal onset in juvenile dermatomyositis (JDMS): an epidemiological study. Arthritis Rheum 1992; 35:S88.
- Pachman LM, Lipton R, Ramsey-Goldman R, et al. History of infection before the onset of juvenile dermatomyositis: results from the National Institute of Arthritis and Musculoskeletal and Skin Diseases Research Registry. Arthritis Rheum 2005; 53:166.
- Manlhiot C, Liang L, Tran D, et al. Assessment of an infectious disease history preceding juvenile dermatomyositis symptom onset. Rheumatology (Oxford) 2008; 47:526.
- Pachman LM, Hayford JR, Hochberg MC, et al. New-onset juvenile dermatomyositis: comparisons with a healthy cohort and children with juvenile rheumatoid arthritis. Arthritis Rheum 1997; 40:1526.
- Pachman LM, Litt DL, Rowley AH, et al. Lack of detection of enteroviral RNA or bacterial DNA in magnetic resonance imaging-directed muscle biopsies from twenty children with active untreated juvenile dermatomyositis. Arthritis Rheum 1995; 38:1513.
- Mamyrova G, Katz JD, Jones RV, et al. Clinical and laboratory features distinguishing juvenile polymyositis and muscular dystrophy. Arthritis Care Res (Hoboken) 2013; 65:1969.
- McCann LJ, Garay SM, Ryan MM, et al. Oropharyngeal dysphagia in juvenile dermatomyositis (JDM): an evaluation of videofluoroscopy swallow study (VFSS) changes in relation to clinical symptoms and objective muscle scores. Rheumatology (Oxford) 2007; 46:1363.
- Dugan EM, Huber AM, Miller FW, et al. Photoessay of the cutaneous manifestations of the idiopathic inflammatory myopathies. Dermatol Online J 2009; 15:1.
- Constantin T, Ponyi A, Orbán I, et al. National registry of patients with juvenile idiopathic inflammatory myopathies in Hungary--clinical characteristics and disease course of 44 patients with juvenile dermatomyositis. Autoimmunity 2006; 39:223.
- Akikusa JD, Tennankore DK, Levin AV, Feldman BM. Eye findings in patients with juvenile dermatomyositis. J Rheumatol 2005; 32:1986.
- COOK CD, ROSEN FS, BANKER BQ. DERMATOMYOSITIS AND FOCAL SCLERODERMA. Pediatr Clin North Am 1963; 10:979.
- Schmeling H, Stephens S, Goia C, et al. Nailfold capillary density is importantly associated over time with muscle and skin disease activity in juvenile dermatomyositis. Rheumatology (Oxford) 2011; 50:885.
- Tse S, Lubelsky S, Gordon M, et al. The arthritis of inflammatory childhood myositis syndromes. J Rheumatol 2001; 28:192.
- Bingham A, Mamyrova G, Rother KI, et al. Predictors of acquired lipodystrophy in juvenile-onset dermatomyositis and a gradient of severity. Medicine (Baltimore) 2008; 87:70.
- Huemer C, Kitson H, Malleson PN, et al. Lipodystrophy in patients with juvenile dermatomyositis--evaluation of clinical and metabolic abnormalities. J Rheumatol 2001; 28:610.
- Verma S, Singh S, Bhalla AK, Khullar M. Study of subcutaneous fat in children with juvenile dermatomyositis. Arthritis Rheum 2006; 55:564.
- Pope E, Janson A, Khambalia A, Feldman B. Childhood acquired lipodystrophy: a retrospective study. J Am Acad Dermatol 2006; 55:947.
- Kobayashi I, Yamada M, Takahashi Y, et al. Interstitial lung disease associated with juvenile dermatomyositis: clinical features and efficacy of cyclosporin A. Rheumatology (Oxford) 2003; 42:371.
- Kobayashi N, Takezaki S, Kobayashi I, et al. Clinical and laboratory features of fatal rapidly progressive interstitial lung disease associated with juvenile dermatomyositis. Rheumatology (Oxford) 2015; 54:784.
- Downey EC Jr, Woolley MM, Hanson V. Required surgical therapy in the pediatric patient with dermatomyositis. Arch Surg 1988; 123:1117.
- Mamyrova G, Kleiner DE, James-Newton L, et al. Late-onset gastrointestinal pain in juvenile dermatomyositis as a manifestation of ischemic ulceration from chronic endarteropathy. Arthritis Rheum 2007; 57:881.
- Mitchell JP, Dennis GJ, Rider LG. Juvenile dermatomyositis presenting with anasarca: A possible indicator of severe disease activity. J Pediatr 2001; 138:942.
- Brown VE, Pilkington CA, Feldman BM, et al. An international consensus survey of the diagnostic criteria for juvenile dermatomyositis (JDM). Rheumatology (Oxford) 2006; 45:990.
- Haas RH, Dyck RF, Dubowitz V, Pepys MB. C-reactive protein in childhood dermatomyositis. Ann Rheum Dis 1982; 41:483.
- Guzmán J, Petty RE, Malleson PN. Monitoring disease activity in juvenile dermatomyositis: the role of von Willebrand factor and muscle enzymes. J Rheumatol 1994; 21:739.
- Bloom BJ, Tucker LB, Miller LC, Schaller JG. von Willebrand factor in juvenile dermatomyositis. J Rheumatol 1995; 22:320.
- Genetic susceptibility
- Immunologic mechanisms
- CLINICAL MANIFESTATIONS
- Muscle weakness
- Cutaneous manifestations
- - Heliotrope rash
- - Gottron's papules
- - Nailfold capillary changes
- - Skin ulcerations
- Pulmonary involvement
- Gastrointestinal vasculopathy
- LABORATORY FINDINGS