Overview of adult dermatomyositis
Dermatomyositis is a rare autoimmune condition characterised by muscle inflammation (myositis) occurring in association with a cutaneous eruption in both adults and children. Juvenile dermatomyositis differs from adult disease; see the separate topic for more detailed information.
Dermatomyositis is responsible for approximately one-third of all cases of idiopathic inflammatory myopathy in adultsSchmidt, 2018. There is a 2:1 female preponderance and it usually presents between 40 to 60 years of ageDeWane, 2020. The clinical course is variable. In amyopathic dermatomyositis, cutaneous features are the only manifestations of the disease.
The prevalence of malignancy associated with adult dermatomyositis is approximately 20%Waldman, 2020 and is more likely in people with specific autoantibodies.
Management for idiopathic inflammatory myopathies is usually under specialist supervision. Refer patients with severe disease, especially severe weakness, dysphagia and risk of aspiration, urgently to a specialist centre.
For clinical features and management of idiopathic inflammatory myopathies other than dermatomyositis in adults, see the separate section.