Overlap myositis

A rare idiopathic inflammatory myopathy (IIM) with a heterogeneous phenotype characterized by myositis with at least one clinical and/or autoantibody overlap feature. Possible clinical overlap features include polyarthritis, Raynaud's phenomenon, sclerodactyly, scleroderma (proximal to metacarpophalangeal joints), lung interstitial pneumonia, and/or clinical signs of systemic lupus erythematosus (SLE).