Diagnosis and classification of amyopathic dermatomyositis. (26th April 2019) - Concha, J.S.S.
Summary: Dermatomyositis is an inflammatory disorder in which characteristic skin lesions (affected patches) are associated with inflammation and weakness of the muscles. Some individuals have muscle changes but no skin signs (inflammatory myopathy), whereas some others have only skin lesions and may never develop muscle inflammation (amyopathic dermatomyositis). Existing criteria for classifying muscle inflammation do not recognise amyopathic dermatomyositis. The authors, based at the University of Pennsylvania, USA, used the PubMed database to search medical literature (i.e. research) from June to August 2018 on the diagnosis and classification of amyopathic dermatomyositis. They found 226 articles on diagnosis and 32 specifically on classification. The current validated criteria for recognising skin features fail to include 25% of patients. Amyopathic dermatomyositis can be misdiagnosed clinically (by the doctor) and histologically (after a tissue sample is looked at under a microscope) as another inflammatory skin disease such as cutaneous lupus erythematosus. It is important to make a diagnosis of dermatomyositis since these people are at greater risk of inflammatory lung disease and internal cancers and should be screened for these conditions. The authors conclude that more specific description of skin lesions is needed to clarify the diagnosis, together with additional information such as the presence of autoantibodies in the blood (which are produced by the immune system to fight off illness), some of which are uniquely found in specific patterns of dermatomyositis. More accurate diagnosis will enable more specific treatment in the future. Abstract : Linked Article: Concha et al. Br J Dermatol 2019; 180 :1001–1008