Review of the classification and assessment of the cutaneous manifestations of the idiopathic inflammatory myopathies.

Adult and juvenile dermatomyositis, polymyositis and myositis overlapping with another connective tissue disease are rare systemic autoimmune diseases with a primary feature of weakness and muscle inflammation. Cutaneous findings specific to the underlying condition are present in many patients with these disorders. Some lesions are highly characteristic of the idiopathic inflammatory myopathies (IIM), especially in dermatomyositis. Some cutaneous findings are common but not specific to the IIM and others are less frequently observed in patients with these illnesses. Many of these manifestations also have different grades of disease activity or damage. This photoessay reviews the classification and assessment of the cutaneous manifestations of the IIM and presents example photographs of many of the lesions of adult and juvenile IIM accumulated from the clinical experience of international experts in these conditions. The purpose of this work is to facilitate better recognition of the diverse cutaneous manifestations associated with these inflammatory myopathies.