Only 10 cases of ISCLS in children have been reported to date [
3‐
11]. These attacks occurred at ages ranging from 5 months to 8 years. Most of the cases were severe or fatal. All patients in reports were previously healthy and only one had a family history of ISCLS. ISCLS should be included in the differential diagnosis of sudden hypovolemic shock with general edema (anaphylaxis, C1-esterase inhibitor deficiency, nephrotic syndrome). Pathogenesis and pathophysiology of ISCLS are relatively unknown. Reports suggest that VEGF and angiopoietin 2 (Ang2) contribute to endothelial contraction and might be associated with pathogenesis [
12]. Elevated levels of cytokines and chemical mediators (G-CSF, IL-6, IL-8 and monocyte chemotactic protein-1: MCP-1) were reported in some cases [
13]. G-CSF and VGEF levels might be a used as biomarkers for the severity and for monitoring the clinical course in ISCLS [
14,
15]. In the present case, G-CSF was elevated, but VEGF was normal in plasma. Surprisingly, VEGF in ascites was elevated. There was a case report that did not show increase of VEGF in plasma as the present case, but the reason is unknown [
16]. Further investigations of various biomarkers, which might play an important role, are needed for clarify the pathophysiology of ISCLS. Although there are no established therapies in acute phase, corticosteroids and IVIG has been used to treat ISCLS attacks [
8,
17]. Recently, it has been reported that a patient with ISCLS after stem cell transplantation was received anti-VEGF antibody bevacizumab despite low serum VEGF level, and improved within 48 hours [
16]. In pediatric case, the tumor necrosis factor alpha (TNF-α) antagonist infliximab was administered when serum TNF-α was increased, and clinical course was developed dramatically [
6]. In present case, methylprednisolone and IVIG could not improve symptoms and the effect of these treatments was limited. Therefore, appropriate fluid management in acute phase is most important. Prophylactic treatment with theophylline and terbutaline as well as IVIG has been shown to reduce frequency and severity of ISCLS attacks, which could be effective in the present case [
8,
18].
In conclusion, ISCLS should be considered in the differential diagnosis when unexplained hypovolemic shock is observed. The diagnostic evaluation should be performed concurrently with initial fluid management. Immediate intervention should be started because ISCLS has a high fatality rate.