TRANSIENT ILEO-ILEAL INTUSSUSCEPTION AS A MANIFESTATION OF MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN

A previously healthy 6-year-old girl was admitted with the complaints of fever, intermittent diarrhoea and abdominal pain which were present for six days. Her medical history was unremarkable except for exposure to her father who had been diagnosed with coronavirus disease 2019 (COVID-19) six weeks prior to the admission. On physical examination, she had conjunctivitis, tachycardia and abdominal tenderness without abdominal distention, rebound, involuntary guarding or rectal bleeding. A plain abdominal radiograph was non-specific (Fig. 1a). Abdominal ultrasound revealed an ileo-ileal intussusception 24 mm in length (Fig. 1b) and fluid retention in the ileal and colonic walls. No lead points such as enlarged lymph nodes were identified. Echocardiography revealed mitral regurgitation, left ventricular systolic dysfunction and an ejection fraction of 55%. Laboratory parameters showed elevated inflammatory markers (C-reactive protein 85 mg/L, erythrocyte sedimentation rate 40 mm/h, procalcitonin 8 ng/mL, interleukin-6 90 pg/mL, ferritin 200 ng/mL and fibrinogen 572 mg/dL), lymphocytopenia (660/mm³) and positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies. Real-time polymerase chain reaction test for COVID-19 was negative. Blood and urine cultures were also negative.

She was diagnosed with multisystem inflammatory syndrome in children (MIS-C) according to the case definition criteria of the US Centers for Disease Control and Prevention (CDC).¹ She was treated with 2 g/kg of intravenous immunoglobulin and 2 mg/kg/day of intravenous methylprednisolone in two divided doses. Fever, conjunctivitis and abdominal pain resolved after treatment. No intervention was needed to treat the intussusception which regressed spontaneously. She was discharged without any complications.

We want to emphasise that our patient's clinical presentation differed from the usual clinical presentation of intussusception. First, she was older than usual, since intussusception typically presents under the age of 36 months.² Second, she did not present with the classic triad of intussusception (acute onset of crampy abdominal pain, a palpable sausage-shaped abdominal mass and redcurrant- jelly stool), although it is known that the classic triad is not seen in most patients, particularly older ones. Third, conjunctivitis and cardiac involvement are not seen in classical intussusception, which led us to think that the intussusception may have been a manifestation of systemic involvement of another disease in our patient.

One of the most important organ system involvements of MIS-C is the gastrointestinal system (GIS). Children may have GIS involvement and can present with a wide spectrum of findings, from mild symptoms to severe findings mimicking acute abdomen which may warrant surgery. Abdominal radiological findings of MIS-C previously reported include ileitis, colitis, mesenteric lymphadenitis, gallbladder wall thickening, bowel dilatation and ascites.³ To our knowledge, no MIS-C cases with intussusception have been reported to date, although intussusception was reported in acute COVID-19 infection and Kawasaki disease.^{4, 5} Our case raises the possibility that transient intussusception may be one of the GIS involvements of MIS-C.

Informed consent has been obtained from parents for including patient details and clinical photographs in the manuscript.

中文翻译：

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暂时性回肠套叠是儿童多系统炎症综合征的表现

一过性回肠套叠是儿童多系统炎症综合征的表现

一名先前健康的 6 岁女孩因发烧、间歇性腹泻和腹痛等症状持续 6 天入院。除了在入院前六周与被诊断出患有 2019 年冠状病毒病 (COVID-19) 的父亲有过接触之外，她的病史没有什么特别之处。查体有结膜炎、心动过速、腹部压痛，无腹胀、反跳痛、不自主守卫或直肠出血。腹部平片是非特异性的（图 1a）。腹部超声显示长度为 24 mm 的回肠套叠（图 1b）和回肠壁和结肠壁的液体潴留。没有发现淋巴结肿大等导联点。超声心动图显示二尖瓣关闭不全，左心室收缩功能障碍，射血分数为 55%。实验室参数显示炎症标志物升高（C 反应蛋白 85 毫克/升，红细胞沉降率 40 毫米/小时，降钙素原 8 纳克/毫升，白介素 6 90 pg/毫升，铁蛋白 200 纳克/毫升和纤维蛋白原 572 毫克/分升） , 淋巴细胞减少 (660/mm³ ) 和阳性严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) IgG 抗体。COVID-19 的实时聚合酶链反应测试呈阴性。血和尿培养也呈阴性。

根据美国疾病控制与预防中心（CDC）的病例定义标准，她被诊断为儿童多系统炎症综合征（MIS-C）。¹她接受了 2 g/kg 静脉注射免疫球蛋白和 2 mg/kg/天静脉注射甲基强的松龙，分两次给药。治疗后发烧、结膜炎和腹痛消退。不需要干预来治疗自发消退的肠套叠。她出院了，没有任何并发​​症。

我们想强调的是，我们患者的临床表现不同于肠套叠的常见临床表现。首先，她比平时大，因为肠套叠通常在 36 个月以下出现。²第二，她没有出现典型的肠套叠三联征（痉挛性腹痛的急性发作、可触及的香肠状腹部肿块和红醋栗果冻大便），尽管已知大多数患者没有出现典型的三联征，特别是年纪大的。第三，经典肠套叠中未见结膜炎和心脏受累，这使我们认为肠套叠可能是我们患者全身受累的另一种疾病的表现。

MIS-C 最重要的器官系统受累之一是胃肠系统 (GIS)。儿童可能有 GIS 受累，并可能表现出广泛的表现，从轻度症状到严重的模仿急腹症的表现，可能需要手术。先前报道的 MIS-C 的腹部放射学发现包括回肠炎、结肠炎、肠系膜淋巴结炎、胆囊壁增厚、肠道扩张和腹水。³据我们所知，尽管在急性 COVID-19 感染和川崎病中报告了肠套叠，但迄今为止尚未报告有肠套叠的 MIS-C 病例。^{4, 5}我们的案例提出了一种可能性，即暂时性肠套叠可能是 MIS-C 的 GIS 参与之一。

在手稿中包含患者详细信息和临床照片已获得父母的知情同意。