Anti-MDA5 dermatomyositis following mild Sars-CoV infections: a systematic review

Anti-MDA5 dermatomyositis (DM), also called anti-MDA5+ syndrome, or clinically amyopathic dermatomyositis (CADM), is characterized by extra-muscular DM manifestations such as skin rash, arthralgia, and rapid progressive-interstitial lung disease. Between 2020 and 2024, an increase in serum titer of anti-MDA5 autoantibodies (AABs) and MDA5+ DM cases was registered among the general population. Given the role of MDA5 as a viral-RNA sensor, it is considered a key molecule in rheumatological disorders, as studies show its activity is triggered by viral infection. Here, we conducted a systematic review of studies reporting an unambiguous temporal link between SARS-CoV-2 infections and development of MDA5+ DM. The aim was to clarify our understanding of this idiopathic rheumatic nature.