[Myositis: current data on the classification, diagnosis and treatment].

Area of Science:

• Rheumatology and Immunology
• Neurology
• Dermatology

Context:

• Idiopathic inflammatory myopathies (IIMs) classification is evolving.
• New autoantibodies and their clinicopathological correlations are being identified.
• The Troyanov classification provides a framework for IIM subtypes.

Purpose:

• To summarize the current understanding of IIM classification.
• To highlight the distinctions between different IIM subtypes.
• To inform on treatment approaches for various myositis forms.

Summary:

• Current IIM classification includes pure polymyositis (PM), dermatomyositis (DM), myositis overlap, cancer-associated myositis, and sporadic inclusion body myositis (IBM).
• Myositis overlap syndromes, characterized by extra-muscular/cutaneous features or autoantibodies, are often more severe and chronic.
• Inclusion body myositis (IBM) presents treatment challenges, with immunosuppressants or immunoglobulins considered early in the disease course.

Impact:

• Refined classification aids in accurate diagnosis and prognosis of IIMs.
• Understanding subtype-specific features improves therapeutic decision-making.
• This knowledge supports the development of targeted treatment strategies for inflammatory myopathies.