Our results suggest that recurrent KFD is more frequent than reported, and recurrent KFD should be considered in children with a history of other systemic illnesses such as immune disorders.

Scrub typhus is a rickettsial disease, caused by Orientia tsutsugamushi, which is transmitted via the bite of a chigger. This disease is one of the most important infectious diseases in the Asia-Pacific area; however, a severe infant case has not yet been reported. Here, we present the case of an 8-month-old boy with scrub typhus accompanied by hemophagocytic lymphohistiocytosis (HLH). His rapid course was complicated by acute respiratory distress syndrome (ARDS), status epilepticus and disseminated intravascular coagulation (DIC). He recovered after clarithromycin therapy and intensive supportive care. Although being extremely rare, scrub typhus can be life-threatening in an infant; therefore, physicians in endemic countries should be aware of the necessity for early recognition and prompt treatment of suspected cases.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare congenital neoplasm that originates from the neural crest cells, which give rise to the melanocytes of the skin and leptomeninges. We report a case of MNTI with neurocutaneous melanosis of a 28-month-old girl. She was born with hydrocephalus and several large congenital giant nevi. There were no findings except for hydrocephalus, after a ventriculoperitoneal (VP) shunt operation performed when she was 6 months old. She was operated on for a growing inguinal mass at 8 months. The specimen from the inguinal sac was positive for HMB45, vimentin, chromogranin, and neuron-specific enolase. Brain magnetic resonance imaging showed an extensive enhancing extra-axial mass with high signal intensity, along the cerebral spinal fluid space. We report a rare case of MNTI, diagnosed from an inguinal hernia sac, with a disseminated clinical manifestation.

Background: Eosinophilic gastrointestinal disorder (EoGID) is an emerging disease condition in Korean children, but its diagnosis requires invasive endoscopic biopsies. Fecal calprotectin (FCal) is a noninvasive biomarker for intestinal inflammation to differentiate organic gastrointestinal diseases from functional abdominal pain disorder. This study aimed to evaluate the diagnostic accuracy of FCal and to determine the optimal cutoff to differentiate EoGID from functional abdominal pain disorder. Methods: A total of 253 children (122 boys, 131 girls; mean age 12.2 ± 3.6, range 2.9-17.8 years) who underwent endoscopy with biopsies for chronic gastrointestinal symptoms were recruited, except for 38 children diagnosed with inflammatory bowel disease, and divided into EoGID (n = 67) and functional abdominal pain disorder (n = 186). FCal, white blood cell (WBC) counts, eosinophil counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were measured in all subjects at initial diagnosis. Results: FCal levels weakly correlated with WBC (r = 0.127, P = 0.044) and CRP (r = 0.126, P = 0.040) but not with ESR and eosinophil count. FCal levels were significantly higher in the EoGID group than in the functional abdominal pain disorder group (mean 179.5 ± 242.9 mg/kg vs. 44.3 ± 68.1 mg/kg; P < 0.001), while WBC, ESR, CRP, and eosinophil count did not differ between the two groups (all P > 0.05). An optimal cutoff of FCal 73.2 mg/kg distinguished EoGID from functional abdominal pain disorder with a sensitivity of 50.7% and a specificity of 84.6%. Conclusion: FCal is a useful and reliable noninvasive marker for differentiating EoGID from functional abdominal pain disorder in Korean children with chronic gastrointestinal symptoms when optimal cutoffs are applied.

Conventional methods for etiologic diagnoses of acute gastroenteritis (AGE) are time consuming and have low positive yield leading to limited clinical value. This study aimed to investigate quality improvements in patient management, antibiotic stewardship, and in-hospital infection transmission prevention using BioFire® FilmArray® Gastrointestinal Panel (GI Panel) in children with acute diarrhea. This was a prospective study recruiting children <19 years old with new onset diarrhea during the study period, and a matched historical cohort study of children diagnosed with AGE during the 4 years prior. Patients in the prospective cohort underwent stool testing with GI Panel and conventional methods. A total of 182 patients were included in the prospective cohort, of which 85.7% (n = 156) had community-onset and 14.3% (n = 26) had hospital-onset diarrhea. A higher pathogen positivity rate for community-onset diarrhea was observed by the GI Panel (58.3%, n = 91) compared to conventional studies (42.3%, n = 66) (p = 0.005) and historical cohort (31.4%, n = 49) (p < 0.001). The stool tests reporting time after admission was 25 (interquartile range, IQR 17–46) hours for the GI Panel, and 72 (IQR 48–96) hours for the historical cohort (p < 0.001). A significant reduction in antibiotic use was observed in the prospective cohort compared to historical cohort, 35.3% vs. 71.8%; p < 0.001), respectively. Compared to the GI Panel, norovirus ICT was only able to detect 4/11 (36.4%) patients with hospital-onset and 14/27 (51.8%) patients with community-onset diarrhea. The high positivity rate and rapid reporting time of the GI Panel had clinical benefits for children admitted for acute diarrhea, especially by reducing antibiotic use and enabling early adequate infection precaution and isolation.

Background: While Helicobacter pylori (H. pylori) ulcers has declined recently, H. pylori-negative and/or gastrotoxic drug-negative peptic ulcers (HNGN-PU) has increased. This study aimed to analyze the etiology of peptic ulcers in children and the differences in clinical, laboratory, endoscopic, and histopathologic findings of peptic ulcers according to etiology, including eosinophilic gastroenteritis (EoGE). Methods: In total, 255 children (157 boys and 98 girls) with peptic ulcers were recruited. The subjects were categorized into 5 groups according to the etiology of the ulcer: 1) H. pylori infection (n = 51); 2) gastrotoxic drugs (n = 18); 3) idiopathic (n = 144); 4) systemic disease (n = 23); 5) EoGE (n = 19). Clinical data were reviewed and analyzed retrospectively. Results: Age at diagnosis, ulcer recurrence, atopic dermatitis history, white blood cell count, blood eosinophil count, platelet count, serum albumin level, iron level, erythrocyte sedimentation rate, and C-reactive protein level differed significantly among the 5 groups (all p < 0.05). Regarding endoscopic findings, multiple ulcers and gastric mucosal nodularity differed among the 5 groups (all p < 0.05). When comparing the EoGE ulcer group with the others, EoGE group revealed older ages (p = 0.022), higher rates of ulcer recurrence (p = 0.018), atopic dermatitis history (p = 0.001), and both blood and tissue eosinophilia (both p = 0.001). Conclusions: EoGE ulcers constituted 10.2% of HNGN-PU in pediatric patients. In children with HNGN-PU, peripheral eosinophilia, ulcer recurrence, and atopic dermatitis history might imply EoGE, necessitating thorough investigation of tissue eosinophils during endoscopic biopsy. Trial registration: A total of 255 children was retrospectively registered between between July 2003 and April 2017.

Background Intussusception refers to the invagination of a part of the intestine into itself. The exact cause for this condition is unknown in most cases. The active implementation of coronavirus disease 2019 (COVID-19) infection control guidelines has reduced the spread of COVID-19 and the incidence of other infectious diseases in children. The current study aimed to identify changes in pediatric intussusception and infectious diseases after the implementation of infection control guidelines and confirm the association between intussusception and contagious diseases. Methods We analyzed the electronic medical records of pediatric patients diagnosed with intussusception from seven hospitals in Korea between January 2017 and December 2020. We used open data from the Korea Disease Control and Prevention Agency to investigate changes in infectious diseases over the same period. Results Altogether, we evaluated 390 children with intussusception. There was a statistically significant decrease in the incidence of monthly visits with intussusception in the COVID-19 period group (9.0 vs. 3.5, P < 0.001). When the monthly incidence of infectious diseases was compared between the pre-COVID-19 and the COVID-19 periods, a statistically significant decrease in respiratory viruses (7979.0 vs. 815.2, P < 0.001), enterovirus infection (262.2 vs. 6.6, P < 0.001), and viral enteritis (916.2 vs. 197.8, P < 0.001) were confirmed in the COVID-19 period. Through interrupted time series analysis, it was confirmed that the incidence of intussusception and viral infectious diseases have drastically decreased since March 2020, when COVID-19 infection control guidelines were actively implemented. Conclusion We confirmed that implementing infection control guidelines during the COVID-19 pandemic resulted in a decrease in intussusception and viral infectious diseases. Through this result, it was possible to indirectly confirm the existing hypothesis that viral infections play a significant role in the pathophysiologic mechanism of intussusception.

The diagnosis of hiatal hernia (HH), causing severe gastroesophageal reflux disease and complications in children with cerebral palsy (CP) is cumbersome because invasive investigations are required for diagnosis. Hip displacement, one of the most common complications in children with CP, can be diagnosed with a simple pelvic radiograph. This study aimed to evaluate the association between the severity of hip displacement and HH and the diagnostic accuracy of Reimers’ hip migration percentage (MP) on pelvic radiography in assessing the presence of HH. A total of 52 children with CP (27 boys, 25 girls; mean age, 6.3 years; range, 0.6–17.4 years) who underwent esophagogastroduodenoscopy, upper gastrointestinal series and pelvic radiography between March 2013 and February 2020 were recruited. Demographic and clinical characteristics, as well as endoscopic and radiological findings, were evaluated and statistically analyzed. HH was defined as ≥ 2 cm proximal displacement of the gastroesophageal junction identified in esophagogastroduodenoscopy or upper gastrointestinal series, and MP was calculated by evaluating the pelvic radiograph. Of the 52 children enrolled in this study, HH was diagnosed in 18 children (34.6%). When the patients were classified and analyzed according to the MP result, HH was observed in 10%, 26.7%, and 70.6% in MP <33%, MP 33%–39%, and MP > 40% groups, respectively (P < .001). The optimal MP cutoff of 36.5% distinguished pediatric CP patients with HH from those without HH with a sensitivity of 78%, specificity of 68%, a positive predictive value of 56.0%, and a negative predictive value of 85.2%, respectively. The application of MP and the severity of hip displacement, which can be easily measured by simple radiography, may be useful and reliable in screening for detecting HH in children with CP. Retrospectively registered. This study was approved by the Institutional Review Board of Seoul National University Bundang Hospital (IRB No. B-2007-627-106).