Clinical characteristics of hemophagocytic lymphohistiocytosis following Kawasaki disease: differentiation from recurrent Kawasaki disease.
BACKGROUND
Our aim was to investigate the clinical pattern of hemophagocytic lymphohistiocytosis following Kawasaki disease (HLH-KD), to enable differentiation of HLH from recurrent or refractory KD and facilitate early diagnosis.


METHODS
We performed a nationwide retrospective survey and reviewed the clinical characteristics of patients with HLH-KD, including the interval between KD and HLH, clinical and laboratory findings, treatment responses, and outcomes, and compared them with historical data for both diseases.


RESULTS
Twelve patients with HLH-KD, including 5 previously reported cases, were recruited. The median age was 6.5 years (range, 9 months-14.7 years). Eight patients were male and 4 were female. The median interval between the first episode of KD and the second visit with recurrent fever was 12 days (3-22 days). Of the 12 children, 2 were initially treated with intravenous IgG (IVIG) for recurrent KD when they presented at the hospital with recurrent fever. Eventually, 10 children received chemotherapy under an HLH protocol and 2 received supportive treatment. Two patients died of combined infections during chemotherapy, 1 was lost to follow up, and 9 remain alive. The overall survival rate at 4 years was 81.1% with a median follow up of 45.1 months.


CONCLUSIONS
A diagnosis of HLH-KD should be considered when symptoms similar to recurrent KD develop within 1 month of the first episode of KD. Our findings will help physicians differentiate between HLH and the recurrent form of KD.
Department of Pediatrics, Hanyang University College of Medicine, Seoul, Korea.
Hae-Ryong
HR
Kang
Department of Pediatrics, Hanyang University College of Medicine, Seoul, Korea.
Yong-Hoon
YH
Kwon
Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea.
Eun-Sun
ES
Yoo
Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea.
Kyung-Ha
KH
Ryu
Department of Pediatrics, Keimyung University, Dongsan Medical Center, Daegu, Korea.
Ji Yoon
JY
Kim
Department of Pediatrics, Keimyung University, Dongsan Medical Center, Daegu, Korea.
Heung-Sik
HS
Kim
Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Korea.
Hwang Min
HM
Kim
Department of Pediatrics, Hanyang University College of Medicine, Seoul, Korea.
Young-Ho
YH
Lee
Hemophagocytic lymphohistiocytosis; Kawasaki disease; Recurrent