Juvenile dermatomyositis with anti-signal recognition particle antibodies: a case report.

Serologic investigation has been explored in inflammatory myopathies in order to define subgroups that can help us predict clinical course, treatment and prognosis. The level of similarity between juvenile and adult myopathies regarding the presence of myositis-specific autoantibodies has not been fully elucidated. We report the case of a 8-year-old girl who presented with a rapid progression of muscle weakness and cutaneous signs consistent with the diagnosis of juvenile dermatomyositis and whose serologic testing revealed the presence of anti-signal recognition particle (SRP) antibodies. So far these antibodies have been described mostly in adult subsets, frequently associated with poorer outcomes and rarely related to cutaneous manifestations. The knowledge of the degree of overlap between paediatric and adult SRP positive myopathies may improve the medical care we provide to these children.