Clinical features of overlap myositis
Overlap myositis (or overlap syndrome) is the most common of the idiopathic inflammatory myopathies, responsible for approximately half of all casesSchmidt, 2018. The most common subtype of overlap myositis is myositis of antisynthetase syndromeSchmidt, 2018.
Overlap myositis is associated with other inflammatory connective tissue diseases, including systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease and Sjögren syndrome. It is characterised by the development of proximal muscle weakness in a person previously diagnosed with an inflammatory connective tissue disease.
Management for overlap myositis is outlined in Management overview for idiopathic inflammatory myopathies.