Disease Info

Disease:Idiopathic Inflammatory Myopathies

Idiopathic Inflammatory Myopathies (IIMs)

Idiopathic inflammatory Myopathies (IIMs) include a large group of autoimmune conditions mainly characterized by the occurrence of muscle inflammation. Included diseases are adult polymyositis (PM), adult dermatomyositis (DM), necrotizing autoimmune myositis, antisynthetase syndrome (ASSD), juvenile DM and PM and inclusion body myositis (IBM).

IIMs not rarely are in overlap with other connective tissue diseases. It is also important, in particular in some cases (eg older patients with DM) to rule out an underlying neoplasm.

In IIMs, muscle weakness may develop either insidiously or acutely, it is generally proximal (neck, shoulders, hips or thighs), with difficulties to climb stairs, get up from a seated position, or lift items above their head. Swallowing difficulties are reported in some cases. In IBM, usually affecting older people, also the muscles of the wrists, ankles and fingers may be involved (easily stumble while walking and difficulties to grasp items).

In DM a reddish or purplish rash on the eyelids, elbows, knees, or knuckles can be present.

Other relevant IIMs involvements are arthritis/arthralgias and Interstitial Lung Disease (ILD), deeply impacting patientsí quality of life/ prognosis, and that may be the presenting disease features. This is particularly true for ASSD, a very peculiar condition between the IIM.



1. 2016 American College of Rheumatology/European League Against Rheumatism criteria for minimal, moderate, and major clinical response in adult dermatomyositis and polymyositis: An International Myositis Assessment and Clinical Studies Group/Paediatric Rheumatology International Trials Organisation Collaborative Initiative
Aggarwal R, Rider LG, Ruperto N, Bayat N, Erman B, Feldman BM, et al.
Ann Rheum Dis. 2017 May;76(5):792-801.

2. Consensus-based recommendations for the management of juvenile dermatomyositis
Enders FB, Bader-Meunier B, Baildam E, Constantin T, Dolezalova P, Feldman BM, et al.
Ann Rheum Dis. 2017 Feb;76(2):329-340.

3. Guidelines on the Use of Intravenous Immune Globulin for Neurologic Conditions
Feasby T, Banwell B, Benstead T, Bril V, Brouwers M, Freedman M, et al.
Transfus Med Rev. 2007 Apr;21(2 Suppl 1):S57-107.

4. Consideration of antisynthetase syndrome features in classifying patients as having idiopathic inflammatory myopathy: comment on the article by Lundberg et al.
Castañeda S, Cavagna L, González-Gay MA; American and European Network of Antisynthetase Syndrome Collaborative Group.
Arthritis Rheumatol. 2018 Mar 7.

5. Development of a consensus core dataset in juvenile dermatomyositis for clinical use to inform research
McCann LJ, Pilkington CA, Huber AM, Ravelli A, Appelbe D, Kirkham JJ, et al.
Ann Rheum Dis. 2018 Feb;77(2):241-250.

6. 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups
Lundberg IE, Tjärnlund A, Bottai M, Werth VP, Pilkington C, Visser M, et al.
Arthritis Rheumatol. 2017 Dec;69(12):2271-2282.

7. Management of Myositis-Related Interstitial Lung Disease
Morisset J, Johnson C, Rich E, Collard HR, Lee JS.
Chest. 2016 Nov;150(5):1118-1128.

9. British Society for Rheumatology Standards, Audit and Guidelines Working Group. British Society for Rheumatology guideline on management of paediatric, adolescent and adult patients with idiopathic inflammatory myopathy
Oldroyd AGS, Lilleker JB, Amin T, Aragon O, Bechman K, Cuthbert V, Galloway J, Gordon P, Gregory WJ, Gunawardena H, Hanna MG, Isenberg D, Jackman J, Kiely PDW, Livermore P, Machado PM, Maillard S, McHugh N, Murphy R, Pilkington C, Prabu A, Rushe P, Spinty S, Swan J, Tahir H, Tansley SL, Truepenny P, Truepenny Y, Warrier K, Yates M, Papadopoulou C, Martin N, McCann L, Chinoy H.
Rheumatology (Oxford). 2022 May 5;61(5):1760-1768.

10. A systematic review and meta-analysis to inform cancer screening guidelines in idiopathic inflammatory myopathies
Oldroyd AGS, Allard AB, Callen JP, Chinoy H, Chung L, Fiorentino D, George MD, Gordon P, Kolstad K, Kurtzman DJB, Machado PM, McHugh NJ, Postolova A, Selva-O’Callaghan A, Schmidt J, Tansley S, Vleugels RA, Werth VP, Aggarwal R.
Rheumatology (Oxford). 2021 Jun 18;60(6):2615-2628. Erratum in: Rheumatology (Oxford). 2021 Nov 3;60(11):5483.

11. Recommendations for the treatment of anti-melanoma differentiation-associated gene 5-positive dermatomyositis-associated rapidly progressive interstitial lung disease
Romero-Bueno F, Diaz Del Campo P, Trallero-Araguás E, Ruiz-Rodríguez JC, Castellvi I, Rodriguez-Nieto MJ, Martínez-Becerra MJ, Sanchez-Pernaute O, Pinal-Fernandez I, Solanich X, Gono T, Gonzalez-Gay MA, Plana MN, Selva-O’Callaghan A; MEDRA5 (Spanish MDA5 Register) group
Semin Arthritis Rheum. 2020 Aug;50(4):776-790.

12. 239th ENMC International Workshop: Classification of dermatomyositis, Amsterdam, the Netherlands, 14-16 December 2018
Mammen AL, Allenbach Y, Stenzel W, Benveniste O; ENMC 239th Workshop Study Group.
Neuromuscul Disord. 2020 Jan;30(1):70-92.

13. Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 5. Connective Tissue Disease Associated Interstitial Lung Disease
Koo SM, Kim SY, Choi SM, Lee HK; Korean Interstitial Lung Diseases Study Group.
Tuberc Respir Dis (Seoul). 2019 Oct;82(4):285-297.

14. French expert opinion for the management of juvenile dermatomyositis
Bader-Meunier B, Gitiaux C, Belot A, Brochard K, Mouy R, Ponce D, Bughin V, Jouen F, Musset L, Allenbach Y, Hachulla E, Maillard H, Meyer A, Bourrat E, Benveniste O; French Network of rare autoimmune, autoinflammatory diseases FAI2R.
Arch Pediatr. 2019 Feb;26(2):120-125.

15. Guidelines of the Brazilian Society of Rheumatology for the treatment of systemic autoimmune myopathies
de Souza FHC, de Araújo DB, Vilela VS, Bezerra MC, Simões RS, Bernardo WM, Miossi R, da Cunha BM, Shinjo SK.
Adv Rheumatol. 2019 Jan 22;59(1):6.

16. 224th ENMC International Workshop: Clinico-sero-pathological classification of immune-mediated necrotizing myopathies Zandvoort, The Netherlands, 14-16 October 2016
Allenbach Y, Mammen AL, Benveniste O, Stenzel W; Immune-Mediated Necrotizing Myopathies Working Group.
Neuromuscul Disord. 2018 Jan;28(1):87-99.

17. Screening for tumours in paraneoplastic syndromes: report of an EFNS task force
Titulaer MJ, Soffietti R, Dalmau J, Gilhus NE, Giometto B, Graus F, et al.
Eur J Neurol. 2011 Jan;18(1):19-e3.

Subscribe to our Newsletter