Background and aims Dermatomyositis (DM) is characterised by chronic inflammation of striated muscle and characteristic cutaneous manifestations. Hemophagocytic syndrome (HPS) is a rare life-threatening condition caused by uncontrolled activation of histiocytes resulting in prominent hemophagocytosis. Particularly, occurrence of HPS in the patients with DM is extremely rare.

Methods We report the first case of HPS in a patient with DM successfully treated in Korea.

Results A 56-year-old female visited our hospital, complaining of general weakness with whole body skin rash for 2 months. She had symmetric proximal muscle weakness and characteristic skin lesions including heliotrope rash, gottron’s papules and V sign. She also had swallowing difficulty proven by abnormal videofluoroscopic swallowing test. Laboratory findings showed anaemia, thrombocytopenia, elevated muscle enzymes, hyperferritinemia and hypertriglyceridemia. The autoimmune profile revealed positive antinuclear antibody (1:160, homogenous pattern) and negative anti-Jo-1 antibody. In addition to electromyography and skeletal muscle biopsy, bone marrow biopsy was performed to find the cause of microangiopathic hemolytic anaemia and thrombocytopenia. Numerous CD68-positive macrophages engulfing erythrocytes and platelets were revealed in bone marrow study. She was finally diagnosed as DM with secondary HPS. After steroid pulse therapy for 3 days, we continued high dose steroid therapy for 1 month. Thereafter, we gradually tapered the steroid and started methotrexate. After 1 year of treatment, she was completely recovered from muscle weakness, swallowing difficulty, skin lesions and cytopenia.

Conclusions With this unique case, we would like to assert that HPS should be considered when cytopenia is observed in the patients with DM and that early aggressive therapy is needed.