FAQ: How Do Clinical Manifestations and Histopathologic Features Vary Across Myositis Subtypes?

July 2026

In this rheumatology FAQ, Audrey Gibson, PA-C, reviews how clinical manifestations and histopathologic features vary across idiopathic inflammatory myopathy subtypes, including dermatomyositis, polymyositis, antisynthetase syndrome, immune-mediated necrotizing myopathy, and inclusion body myositis. This clinically focused discussion highlights the key differences in muscle weakness patterns, skin findings, interstitial lung disease, malignancy risk, autoantibody associations, and muscle biopsy findings that help guide diagnosis, prognosis, monitoring, and treatment decisions. Audrey also explores hallmark histopathologic features such as perifascicular atrophy, endomysial inflammation, perimysial pathology, muscle fiber necrosis, rimmed vacuoles, and inclusion bodies. Designed for rheumatology advanced practice providers and clinicians, this FAQ offers practical insights to support earlier recognition, subtype-specific evaluation, multidisciplinary care, and more personalized management of patients with inflammatory myopathies.