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

5. 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.

6. 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.

7. 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.

8. 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.

9. The wound/burn guidelines – 4: Guidelines for the management of skin ulcers associated with connective tissue disease/vasculitis
Fujimoto M, Asano Y, Ishii T, Ogawa F, Kawakami T, Kodera M, et al.
J Dermatol. 2016 Jul;43(7):729-57.

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