Coronavirus 2019 disease in children can present with an immune-mediated syndrome sharing some characteristics with Kawasaki disease and toxic shock syndrome.1 The distinctness of the Coronavirus 2019 induced immune-mediated syndrome has warranted its exclusive designation as multisystem inflammatory syndrome in children (MIS-C).2,3 Abdominal symptoms are common in children with MIS-C,4 We report abdominal imaging findings in 7 children admitted with MIS-C and describe the clinical course of 2 children presenting with acute abdomen with significant findings on CT (Fig. 1).
After Institutional Review Board approval, retrospective data were collected in children 1 month to 18 years of age presenting with MIS-C who had abdominal sonography or computed tomography (CT) performed for evaluation of acute abdomen. All children admitted to a tertiary, urban pediatric intensive care unit with MIS-C from April 2020 to August 2020 were included. Criteria used to define MIS-C were per the case definition set forth by the Centers for Disease Control.5
During the study period, a total of 23 children were admitted to the pediatric intensive care unit with MIS-C, of which 7 (30%) had abdominal imaging. Table 1 describes their clinical, laboratory, and imaging results. Two patients (patient 3 and patient 4) had a more severe clinical presentation.
Patient 3 was an 11-year old healthy male who presented with right lower quadrant abdominal pain, rash, and fever of 2 days duration. He was found to have significant tenderness of the right lower quadrant with pain on movement of extremities. Ultrasound showed a non-compressible, dilated appendix suggestive of acute appendicitis. CT demonstrated appendiceal dilation, mural thickening of the appendix and ascending colon, free fluid within the pelvis, and enlarged lymph nodes in the right hemiabdomen with diffuse mesenteric fat stranding. Bilateral lower lung consolidations were also seen. This patient received conservative treatment of suspected appendicitis with intravenous antibiotics, nil per os, and gastric drainage while also receiving treatment for MIS-C with intravenous immunoglobulin, high-dose aspirin, and steroids. He successfully recovered and was discharged home after 5 days.
Patient 4 was a 16-year-old male with history of asthma, who presented with high-grade fever, chest tightness, multiple episodes of diarrhea and vomiting, generalized body aches, severe periumbilical pain and right lower abdominal pain, and shock. Shock was refractory to fluid resuscitation necessitating institution of norepinephrine and milrinone. COVID-PCR was negative. This patient presented before MIS-C had been described in the literature and antibody testing was available. Though there was a strong suspicion for coronavirus 2019-related disease, his clinical presentation warranted evaluation for perforated appendicitis with abdominal CT. Although the CT demonstrated a normal appendix, there were mural thickening and enhancement of the terminal ileum, diffuse mesenteric, lower abdominal, and retroperitoneal lymphadenopathy, and moderate ascites. Vasculitis was seen at the apex of the aortic arch and proximal aspect of the right brachiocephalic trunk. Bilateral lung consolidations with moderate pleural effusions were also present. An echocardiogram confirmed moderately reduced ventricular function. The patient was managed with noninvasive ventilation, tocilizumab, antibiotics, fluid resuscitation and vasoactive medications. He had a dramatic response to tocilizumab, with resolution of shock and need for noninvasive ventilation. He was discharged home after 7 days in the hospital.
Our patients displayed a range of findings on abdominal imaging. Hepatomegaly was universally present on sonography. Other findings included nephromegaly, gallbladder wall thickening, ascites, mesenteric lymphadenopathy, and increased renal echogenicity. CT findings were remarkable in 2 teenage patients for diffuse bowel wall inflammation, diffuse lymph node enlargement including retroperitoneal lymphadenopathy, and large vessel vasculitis. To our knowledge, large vessel vasculitis has not yet been reported in association with MIS-C.
Hameed et al6 described findings of ascites and right iliac fossa lymphadenopathy on sonography and CT in a subset of children with MIS-C. Riphagen et al,7 in one of the earliest reports of hyperinflammatory shock in children, report ileitis and ascites in 3 patients on abdominal imaging. Tullie et al8 reported inflammatory changes and right lower quadrant lymphadenopathy in 8 children presenting with acute COVID-19 infection, with most of their patients being PCR positive for SARS-CoV2. It is interesting that we found similar changes on abdominal imaging with MIS-C.
Kawasaki disease, presenting occasionally with prominent abdominal symptoms in children, is associated with gallbladder hydrops, splenic infarcts, intestinal obstruction, and ascites.9,10 Further discovery of abdominal involvement in MIS-C may shed light on differences between Kawasaki disease. Differentiating acute appendicitis from abdominal MIS-C may be difficult both clinically and on CT given that frank appendiceal and right iliac fossa inflammation can be seen in both conditions.11 Availability of rapid PCR and antibody testing for COVID-19 may be vital in differentiating acute abdomen from MIS-C.
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. Accessed September 14, 2020
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