Dermatomyositis en polymyositis

Dermatomyositis (DM) and polymyositis (PM) are part of the idiopathic inflammatory myopathies (IIM). The pathogenesis of these diseases has not been fully elucidated. Humoral immune mechanisms and immune complex mediated vasculopathy and complement activation are thought to play a role in DM. In PM and sporadic inclusion-body myositis the cellular immune system seems to play a more important role. DM is diagnosed according to certain criteria that have been formulated. There is an increased risk of underlying malignancies as well as an increase in mortality from those malignant diseases. The therapy of inflammatory myopathy is aimed at improving muscle power and alleviation of other complaints such as skin lesions. There are no controlled studies concerning treatment regimen in IIM. A better understanding of the pathogenesis of these idiopathic inflammatory myopathies may eventually lead to better therapy advice for these diseases.