signs and symptoms in part explain the observation that the average time from onset of symptoms to diagnosis in U.S children is typically several years It is likely that ED physicians frequently come in contact with patients with undiagnosed CD who present with nonspecific abdominal or systemic complaints Initial testing for CD should be via the measurement of IgA antibody to human recombinant tissue transglutaminase (anti-TTG) and anti-endomysial antibodies Intestinal biopsy may also be helpful, but is out of the scope of ED practice and this review The only effective treatment of CD is the complete avoidance of gluten-containing grains Early diagnosis of the disease and dietary elimination of gluten are currently the only ways to avoid complications of the disease that may manifest in adulthood, including intestinal lymphoma and diabetes mellitus A gluten-free diet should result in the resolution of GI symptoms and non-GI symptoms including improved growth and bone mineralization Poor adherence to a gluten-free diet is often responsible for a lack of symptom resolution or recurrence of symptoms and may be assessed through repeat IgA anti-TTG testing Mesenteric Lymphadenitis Mesenteric lymphadenitis (ML) or mesenteric adenitis is typically used to refer to an inflammatory process involving abdominal lymph nodes that leads to acute abdominal pain, and is often identified when evaluating for other common causes of abdominal pain such as appendicitis ML is thought to be more common in younger children (under age of 10), whereas appendicitis is more common in children over the age of 10 While the incidence is unknown, ML is likely a common and important cause of both acute and recurrent abdominal pain in children It is often associated with viral upper respiratory infections It may also be associated with particular bacterial infections (see Chapters 47 Lymphadenopathy and 94 Infectious Disease Emergencies ) Patients often present with fever and right lower quadrant pain, which may mimic appendicitis, intussusception, or other abdominal disease processes Blood tests are of little utility Ultrasound may demonstrate multiple, enlarged lymph nodes (multiple short-axis diameter nodes of mm or more) Most importantly, no alternative diagnosis should be identified The disease is selflimited and will resolve with supportive care over days to several weeks Reye Syndrome Reye syndrome is a distinct, reversible syndrome occurring after an antecedent viral infection, characterized by severe noninflammatory encephalopathy and fatty degeneration of the liver Once the link between antecedent aspirin exposure and the onset of Reye syndrome was established, the incidence has declined to about two cases per year Isolated case reports continue to be described, indicating the need to continue to consider Reye syndrome when evaluating patients with the typical clinical presentation Most of the clinical features of Reye syndrome, including lactic acidosis, elevated fatty acids, nitrogen wasting, hyperammonemia, cellular fat accumulation, and cytotoxic cerebral edema, may be explained in the context of primary mitochondrial damage A biphasic clinical history is remarkably constant First, the child has a history of a recent, usually febrile, illness that is waning or has resolved Approximately 90% of the children have an antecedent upper respiratory tract infection Varicella virus or influenza B infections have been most associated The abrupt onset of protracted vomiting usually starts within week following the prodromal illness The vomiting is unresponsive either to restriction of oral intake or to antiemetic therapy Coincident with the onset of vomiting (or shortly thereafter), signs of encephalopathy appear At first, encephalopathy may be manifested by unusual quietness or disinterest However, a rapid sequential progression to irritability, combativeness, confusion, disorientation, delirium, stupor, and coma may occur Seizures are a late sign in older children but may occur during early stages of encephalopathy in infancy (usually secondary to hypoglycemia) In the ED, patients are usually afebrile Tachycardia and hyperventilation commonly occur At the initial presentation, only 50% of patients have hepatomegaly The liver usually increases in size during the first 24 to 48 hours after the diagnosis is made The absence of jaundice and scleral icterus is characteristic and is the major mitigating clinical sign against hepatic encephalopathy secondary to acute fulminant hepatitis Despite evidence of encephalopathy, no focal neurologic signs or signs of meningeal irritation are apparent The hallmark of the acute encephalopathy of Reye syndrome is the associated evidence of liver abnormality The levels of transaminases (ALT and AST) and blood ammonia are almost always elevated at the time of the onset of protracted vomiting The range of transaminase elevation is highly variable and has not been shown to correlate well with severity of the disease Ammonia levels more than 300 g/L have been shown to be an indicator of a poor prognosis The PT is elevated by more than 50% in at least one-half of the patients, although clinical bleeding is rare and evidence of disseminated intravascular coagulation is absent The level of serum bilirubin rarely exceeds mg/dL Hypoglycemia is rare, except in children who present in coma and in infants younger than year, in whom the incidence is reported to be as high as 70% to 80% Azotemia and ketonuria are common, secondary to starvation and dehydration from vomiting and poor oral intake Patients most often have a mixed respiratory alkalosis and mild metabolic acidosis The metabolic acidosis correlates with the level of ammonia elevation and reflects the degree of mitochondrial dysfunction Once the diagnosis is made, immediate plans to admit the child to an ICU should be made, because the progression of the encephalopathy may be rapid, resulting in increased morbidity and mortality Increased ICP secondary to cerebral edema is the major factor contributing to morbidity and mortality With the ability to monitor ICP, numerous different invasive therapies have been introduced in an attempt to rapidly reduce and control cerebral edema However, none of these therapies, including hyperventilation and muscle paralysis using neuromuscular-blocking drugs, hyperosmolar agents, high-dose barbiturates, exchange transfusions, or hypothermia, have been clearly proven to protect the brain from progressive ischemic insult Ultimately, the management of Reye syndrome is supportive because no specific curative therapy is currently available Finally, it is important to note that there are multiple diseases secondary to inborn errors of metabolism (mostly mitochondrial) that present in a very similar fashion to Reye syndrome Given the rarity of Reye syndrome, any child who is suspected of having Reye syndrome should have a thorough metabolic evaluation Suggested Readings and Key References Overview Thompson DA, Eitel D, Fernandes CM, et al Coded chief complaints– automated analysis of free-text complaints Acad Emerg Med 2006;13(7):774–782 Gastrointestinal Bleeding Alarcon T, Jose Martinez-Gomez M, Urruzuno P Helicobacter pylori in pediatrics Helicobacter 2013;18(suppl 1):52–57 Ertem D Clinical practice: Helicobacter pylori infection in childhood Eur J Pediatr 2013;172(11):1427–1434 Hernandez C, Serrano C, Einisman H, et al Peptic ulcer disease in Helicobacter pylori-infected children: clinical findings and mucosal immune response J Pediatr Gastroenterol Nutr 2014;59(6):773–778 Jones NL, Koletzko S, Goodman KJ, et al Joint ESPGHAN/NASPGHAN guidelines for the management of Helicobacter pylori in children and adolescents (update 2016) J Pediatr Gastroenterol Nutr 2011;53(2):7646991-1003 Oderda G, Mura S, Valori A, et al Idiopathic peptic ulcers in children J Pediatr Gastroenterol Nutr 2009;48(3):268–270 Reid-Adam J Henoch-Schönlein purpura Pediatr Rev 2014;35(10):447–449 Esophageal Varices D’Antiga L Medical management of esophageal varices and portal hypertension in children Semin Pediatr Surg 2012;21(3):211–218 Fagundes ED, Ferreira AR, Roquete ML, et al Clinical and laboratory predictors of esophageal varices in children and adolescents with portal hypertension syndrome J Pediatr Gastroenterol Nutr 2008;46(2):178–183 Lykavieris P, Gautheir F, Hadchouel P, et al Risk of gastrointestinal bleeding during adolescence and early adulthood in children with portal vein obstruction J Pediatr 2000;136(6):805–808 Shneider BL, Bosch J, de Franchis R, et al; Expert panel of the Children’s Hospital of Pittsburgh of UPMC Portal hypertension in children: expert pediatric opinion on the report of the Baveno v Consensus Workshop on Methodology of Diagnosis and Therapy in Portal Hypertension Pediatr Transplant 2012;16(5):426–437 Villanueva C, Colomo A, Bosch A, et al Transfusion strategies for acute upper gastrointestinal bleeding N Engl J Med 2013;368(1):11–21 Inflammatory Bowel Disease Church PC, Guan J, Walters TD, et al Infliximab maintains durable response and facilitates catch-up growth in luminal pediatric Crohn’s disease Inflamm Bowel Dis 2014;20(7):1177–1186 ... Gastrointestinal Bleeding Alarcon T, Jose Martinez-Gomez M, Urruzuno P Helicobacter pylori in pediatrics Helicobacter 2013;18(suppl 1):52–57 Ertem D Clinical practice: Helicobacter pylori infection... panel of the Children’s Hospital of Pittsburgh of UPMC Portal hypertension in children: expert pediatric opinion on the report of the Baveno v Consensus Workshop on Methodology of Diagnosis and... Walters TD, et al Infliximab maintains durable response and facilitates catch-up growth in luminal pediatric Crohn’s disease Inflamm Bowel Dis 2014;20(7):1177–1186