Use many major types of idiopathic inflammatory myopathies exist, the nature of weakness seen in polymyositis, and malignancy screening required in polymyositis to frame the working diagnosis and next step; treat it as a safety constraint before prescribing or reassuring. Make the nature of weakness seen in polymyositis the checkpoint that determines whether you escalate testing, narrow the differential, or change treatment.

Just like with dermatomyositis and necrotizing myositis, polymyositis carries an increased risk of underlying malignancy, so screening is required; That specific presentation is classic for inclusion body myositis; Polymyositis typically presents with a slow, progressive onset of muscle weakness that is both proximal and symmetric; Four major types to keep in mind: dermatomyositis, polymyositis, inclusion body myositis, and necrotizing autoimmune myositis; While myotonic dystrophy can occasionally present with a similar mix, it is typically symmetric