Introduction
Synonyms: Dermatomyositis Idiopathic inflammatory myopathies Idiopathic inflammatory dermatomyopathies
Key features
Autoimmune connective tissue disease of uncertain etiology with both juvenile and adult forms
Clinical and laboratory signs of proximal extensor inflammatory myopathy
Distinctive, photodistributed, pink–violet poikiloderma favoring the scalp, periocular region, and extensor surfaces, in addition to distinctive nail-fold changes and pink–violet papules overlying the knuckles
Histopathologic evidence of interface dermatitis plus mucin deposition in skin biopsy specimens and lymphocytic myositis in biopsy specimens from affected muscle
When myositis is present, therapy includes systemic corticosteroids and steroid-sparing immunosuppressive and immunomodulatory drugs, with the prognosis being very good, except for those individuals with refractory myositis, systemic involvement, or an associated advanced malignancy
Management of cutaneous dermatomyositis via skin-directed therapies can be challenging and is directed by disease severity