Juvenile Dermatomyositis with a rare and severe complication: Macrophage Activation Syndrome

Juvenile dermatomyositis is the most common idiopathic inflamatuary myositis in children. It is a rare, chronic, vasculopathic, autoimmune disorder characterized by symmetrical proximal muscle weakness and pathognomonic skin rash. Macrophage activation syndrome (MAS) is a severe and life theratening complication seen in the patients of chronic rheumatic diseases of childhood. We reported a 12 year old girl presented with macrophage activation syndrome due to juvenile dermatomyositis. She had proximal muscle weakness, heliotrope rash, high level of aldolase as spesific muscle enzyme, typical myositis findings on MRI. According to the diagnostic criteria of HLH- 2004 macrophage activation syndrome was considered secondary to juvenile dermatomyositis. Fever, splenomegaly, cytopenia, hypertrigliseridemia, hemophagocytosis was present. The patient treated with intravenous immunglobulin and metotrexate. After this treatment muscle weakness was improved day by day. On the fifteenth day of this treatment, proximal upper and lower, neck and shoulder motor extremity strength was improved dramatically. In conclusion, we want to represent that JDM is rare condition of MAS and also want to offer treatment approach. MAS should be come in mind each time patient with the diagnosis autoimmune disease. Also it should be considered when unexpected situation is encountered during course of the disease and should and treated immediately.