Hemophagocytic lymphohistiocytosis prior to the diagnosis of Kawasaki disease.

A 9-year-old girl was hospitalized on 7th day of illness because of prolonged fever and cervical lymphadenopathy. On admission, leukopenia (total leukocyte count 1.1×109/L) and thrombocytopenia (platelet count 60×109/L) were present. Serum aspartate aminotransferase (128 U/L), alanine aminotransferase (99 U/ L), lactate dehydrogenase (518 U/L), ferritin (823 mg/ dL), soluble interleukin-2 receptor (1,636 U/mL), interleukin-8 (371 pg/mL) and interferon (IFN)-γ (541 pg/ mL) levels were elevated. Triglyceride and C-reactive protein levels were normal. Coagulation studies revealed increased d-dimer levels. A bone marrow aspiration revealed appreciable numbers of hemophagocytosing macrophages. Serology for cytomegalovirus, EpsteinBarr virus and human parvovirus B19 was negative. On 2nd day of hospitalization, conjunctival injection, lip erythema and erythematous papules appeared. There was no hepatosplenomegaly. Echocardiogram showed dilation of right coronary artery. The patient was diagnosed as having Kawasaki disease complicated by hemophagocytic lymphohistiocytosis (HLH) like illness. Clinical symptoms and laboratory findings improved after the initiations of intravenous immunoglobulin (2 g/ kg/dose) and flurbiprofen (4.5 mg/kg/day). Coronary artery lesion regressed at the 13th day of illness.