在美国,特发性炎性肌病的年发病率为百万分之 5.5 至 10。[1]Karpati G, Hilton-Jones D, Griggs RC. Disorders of voluntary muscle. 7th ed. Cambridge, UK: Cambridge University Press; 2001.[11]Medsger TA, Dawson WN Jr, Masi AT. The epidemiology of polymyositis. Am J Med. 1970;48:715-723.http://www.ncbi.nlm.nih.gov/pubmed/5420557?tool=bestpractice.com随着年龄的增长,年发病率从百万分之2.5(15 岁以下)增长为百万分之10.5(65 岁以上)。[12]Oddis CV, Conte CG, Steen VD, et al. Incidence of polymyositis-dermatomyositis: a 20-year study of hospital diagnosed cases in Allegheny County, PA 1963-1982. J Rheumatol. 1990;17:1329-1334.http://www.ncbi.nlm.nih.gov/pubmed/2254890?tool=bestpractice.com发病率为百万分之 25 到 35.3。[13]Darin N, Tulinius M. Neuromuscular disorders in childhood: a descriptive epidemiological study from western Sweden. Neuromuscul Disord. 2000;10:1-9.http://www.ncbi.nlm.nih.gov/pubmed/10677857?tool=bestpractice.com[14]Phillips BA, Zilko PJ, Mastaglia FL. Prevalence of sporadic inclusion body myositis in Western Australia. Muscle Nerve. 2000;23:970-972.http://www.ncbi.nlm.nih.gov/pubmed/10842277?tool=bestpractice.com
在英国,2006 年至 2007 年 1 年期间,共计有 1819 例皮肌炎患者入院记录。[15]Health & Social Care Information Centre. Hospital Episode Statistics (HES). http://www.hesonline.nhs.uk (last accessed 4 April 2016).http://www.hesonline.nhs.uk/Ease/servlet/ContentServer?siteID=1937&categoryID=205皮肌炎对儿童与成人均有影响。英国住院病例中,约一半的患者介于 15 至 59 岁。女性比男性发病率更高。[1]Karpati G, Hilton-Jones D, Griggs RC. Disorders of voluntary muscle. 7th ed. Cambridge, UK: Cambridge University Press; 2001.[16]Bohan A, Peter JB. Polymyositis and dermatomyositis (first of two parts). N Engl J Med. 1975;292:344-347.http://www.ncbi.nlm.nih.gov/pubmed/1090839?tool=bestpractice.com[5]Engel A, Franzini-Armstrong C. Myology: basic and clinical. 3rd ed. New York: McGraw-Hill, Medical Publishing Division; 2004.西班牙的发病资料提示,每年每百万人群中有 2.2 至 10.6 人患有该疾病。[17]Vargas-Leguas H, Selva-O'Callaghan A, Campins-Marti M, et al. Polymyositis-dermatomyositis: incidence in Spain (1997-2004) [in Spanish]. Med Clin (Barc) 2007;129:721-724.http://www.ncbi.nlm.nih.gov/pubmed/18053482?tool=bestpractice.com
多发性肌炎发生在十岁到二十岁这个年龄段,儿童期则比较罕见。女性具有比较高的发病率。[1]Karpati G, Hilton-Jones D, Griggs RC. Disorders of voluntary muscle. 7th ed. Cambridge, UK: Cambridge University Press; 2001.[16]Bohan A, Peter JB. Polymyositis and dermatomyositis (first of two parts). N Engl J Med. 1975;292:344-347.http://www.ncbi.nlm.nih.gov/pubmed/1090839?tool=bestpractice.com[5]Engel A, Franzini-Armstrong C. Myology: basic and clinical. 3rd ed. New York: McGraw-Hill, Medical Publishing Division; 2004.据估计,西班牙每年每百万人群中有 2.9 至 8.6 人患有多发性肌炎。[17]Vargas-Leguas H, Selva-O'Callaghan A, Campins-Marti M, et al. Polymyositis-dermatomyositis: incidence in Spain (1997-2004) [in Spanish]. Med Clin (Barc) 2007;129:721-724.http://www.ncbi.nlm.nih.gov/pubmed/18053482?tool=bestpractice.com在澳大利亚,每年每百万人群中有 7.4 人患有炎性肌病。[18]Patrick M, Buchbinder R, Jolley D, et al. Incidence of inflammatory myopathies in Victoria, Australia, and evidence of apatial clustering. J Rheumatol. 1999;26:1094-1100.http://www.ncbi.nlm.nih.gov/pubmed/10332974?tool=bestpractice.com
包涵体肌炎流行病学资料比较少。据报导,荷兰每百万人群中有 4.9 例患者。[19]Badrising UA, Maat-Schieman M, van Duinen SG, et al. Epidemiology of inclusion body myositis in the Netherlands: a nationwide study. Neurology. 2000;55:1385-1387.http://www.ncbi.nlm.nih.gov/pubmed/11087787?tool=bestpractice.com包涵体肌炎男性患者比女性患者多 3 倍,50 岁以上的人更可能患有该疾病。与黑人相比,包涵体肌炎更常见于白人中;而对于多发性肌炎和皮肌炎,黑人患者则比白人患者更常见。[1]Karpati G, Hilton-Jones D, Griggs RC. Disorders of voluntary muscle. 7th ed. Cambridge, UK: Cambridge University Press; 2001.[2]Carpenter S, Karpati G. Pathology of skeletal muscle. 2nd ed. New York, NY: Oxford University Press USA; 2001.[11]Medsger TA, Dawson WN Jr, Masi AT. The epidemiology of polymyositis. Am J Med. 1970;48:715-723.http://www.ncbi.nlm.nih.gov/pubmed/5420557?tool=bestpractice.com[12]Oddis CV, Conte CG, Steen VD, et al. Incidence of polymyositis-dermatomyositis: a 20-year study of hospital diagnosed cases in Allegheny County, PA 1963-1982. J Rheumatol. 1990;17:1329-1334.http://www.ncbi.nlm.nih.gov/pubmed/2254890?tool=bestpractice.com