Article in Japanese

A case of transient hypercytokinemia mimicking systemic juvenile idiopathic arthritis following non-typhoidal Salmonella enterocolitis

Masahiro Yano^{1, 2）}, Shojiro Watanabe^1）, Maki Hikita^1）, Yuichiro Yagi^{1, 3）}, Kyoko Konishi^3）, Rituko Shigemi^3）, Takaharu Yoshimatsu^1,4）, Mariko Eguchi^1）

It is well known that non-typhoidal Salmonella infections can cause enterocolitis as well as serious extraintestinal complications such as osteomyelitis, encephalopathy and sepsis. However, the details of post-non-typhoidal Salmonella infection hypercytokinemia remain unknown. Here, we report a pediatric case of hypercytokinemia mimicking systemic juvenile idiopathic arthritis (sJIA) following Salmonella enteritidis enterocolitis. A 4-year-old boy was referred to our hospital for a high fever that began 6 days after recovering from S. enteritidis enterocolitis. The patient presented with intermittent fever, arthralgia, and a salmon pink rash during the fever. Enhanced computed tomography showed enlarged lymph nodes and hepatosplenomegaly. A blood culture was negative, and a bone marrow biopsy showed no evidence of malignancy. Positron emission tomography–computed tomography revealed an excessive accumulation of 18F-fludeoxyglucose in the red bone marrow, indicative of severe systemic inflammation. Cytokine measurement showed increase of interleukin-18 level, and natural killer cell activity was suppressed, suggesting a common mechanism with the cytokine storm in sJIA. These results and symptoms overlapped with sJIA, but the symptoms including intermittent fever resolved spontaneously, which led to the diagnosis of hypercytokinemia after S. enteritidis enterocolitis. Although further studies are required, this case suggests that hypercytokinemia could occur after non-typhoidal Salmonella enterocolitis, at least in part, by a common mechanism as sJIA, even in healthy children.

---

1）Department of Paediatrics, Ehime University Hospital
2）Department of Paediatrics, Ehime Prefectural Imabari Hospital
3）Department of Paediatrics, Matsuyama Shimin Hospital
4）Department of Paediatrics, Saijo Central Hospital

Key words	Salmonella infection, hypercytokinemia, systemic juvenile idiopathic arthritis, interleukin-18, natural killer cell activity
Received	February 4, 2024
Accepted	October 14, 2024

36 (4)：366─371,2024