Dermatomyositis (DM) patients with MDA5 antibody often show rapidly progressive internal pneumonia leading to a fatal course. MDA5 is an essential intracellular sensor for several viruses, including picornavirus. Enterovirus 71 and coxsackievirus A16 belong to picornavirus family, and cause hand-foot-mouth disease. We examined the relationship between MDA5 antibody and enterovirus 71 and coxsackievirus A16 in five DM cases with MDA5 antibody. The antibody for coxsackievirus A16 was elevated in four cases, and that of enterovirus 71was increased in three cases. We may suggest that enterovirus 71 and coxsackievirus A16 infection during the adulthood may be one of the triggers for DM with anti-MDA5 antibody.

The trigger factor of dermatomyositis with anti-MDA5 antibody may be enterovirus 71