Current Treatment Options in Rheumatology

, Volume 4, Issue 4, pp 329–343 | Cite as

Myositis Mimics—a Clinical Approach to a Diagnostic Challenge

  • Sachiko Takahashi
  • Michael NicolleEmail author
Other CTD: Inflammatory Myopathies and Sjögren's (P Basharat, Section Editor)
Part of the following topical collections:
  1. Topical Collection on Other CTD: Inflammatory Myopathies and Sjogren's


Purpose of the Review

Idiopathic inflammatory myopathies (IIMs) encompass a heterogeneous group of disorders generally referred to as myositis. Myositis mimics are common and their overlapping features with IIMs can pose a diagnostic challenge. This review highlights the current knowledge of various myositis mimics, analyzes key distinguishing features from IIMs, and summarizes practical tips in assessing a patient with possible myositis.

Recent Findings

A new classification criteria for IIMs has been proposed by the European League against Rheumatism/American College of Rheumatology in 2017. Advances in medical genetics have expanded the spectrum of hereditary myopathies, and effective treatment has become available for some. Magnetic resonance imaging (MRI), although not without limitations, is more widely used to differentiate myositis mimics from IIMs. In the end, one must consider the clinical gestalt in formulating a diagnosis.


A good clinical history, examination, and judicious use and interpretation of ancillary tests are key in approaching a patient with possible IIMs. Monitoring treatment response is also paramount, not only as a clue to reconsidering the diagnosis but also to prevent unwanted side effects and symptom exacerbation from steroids.


Myositis Idiopathic inflammatory myopathies Mimics 


Compliance with Ethical Standards

Conflict of Interest

Sachiko Takahashi declares that she has no conflict of interest. Michael Nicolle declares that he has no conflict of interest.

Human and Animal Rights and Informed Consent

The authors have not performed any studies involving human or animal subjects in this article.

References and Recommended Reading

Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

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© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.London Health Sciences CentreUniversity HospitalLondonCanada
  2. 2.Division of Neurology, Department of Clinical Neurosciences, Schulich School of Medicine and DentistryWestern UniversityLondonCanada

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