Dermatomyositis during COVID-19 Pandemic (A Case Series): Is there a Cause Effect Relationship?

Viruses have been shown to modify the clinical picture of several autoimmune diseases, including type 1 diabetes, systemic lupus erythematosus (SLE), rheumatoid arthritis and multiple sclerosis. Viral infections have also been considered as a possible trigger for autoimmune disorders like myositis through myositis specific antibodies. Dermatomyositis is an acquired inflammatory myopathy which is relatively rare with incidence of 9.3 per 1 million persons. Usually we come across 1-2 patients of dermatomyositis per year, amongst 800-1000 new patients in our tertiary care rheumatology services. A surge in the incidence was noted this year during the months of April-August of 2020, the period coinciding with the occurrence of corona virus (COVID-19) pandemic in the city of Mumbai, the total number of cases encountered being five in a span of six months. The following case series includes five such cases with review of available literature on virus-triggered autoimmunity with special reference to SARS-CoV-2 and the challenges of immunosuppression during this pandemic.