Eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EE) is an isolated, eosinophilic inflammation of the esophagus. In the past, the symptoms of EE were often confused for gastroesophageal reflux (GER). Thus, many physicians unsuccessfully treated patients with EE with medications used for GER. Because the incidence of EE is rising and EE is easily diagnosed by endoscopy with biopsy, it is important for physicians to not only accurately identify patients with EE but also understand the treatment options available.

RECENT FINDINGS

While patients with acid reflux may have a few eosinophils, patients with EE have high levels of eosinophils in their esophagus as part of an allergic response to food antigens. The inflammation may cause abdominal pain, nausea, or vomiting. If EE persists for years, it may cause a narrowing of the esophagus that leads to dysphagia. In young children, many of the symptoms of EE mimic those of gastroesophageal reflux. Medications used to treat reflux are not effective against EE. Over the past few years, many new reports and retrospective studies have been written on the subject of EE. The focus of these papers concentrated on the etiology and treatment of EE.

SUMMARY

The diagnosis of EE requires a biopsy of the esophagus. Typical allergy tests are not effective for diagnosis of EE because the allergic reaction involved in EE is non-IgE mediated. The most commonly involved foods include milk, eggs, nuts, beef, wheat, fish, shellfish, corn, and soy; however, almost all foods have been implicated. Because allergy tests are often unable to determine the causative foods, complete elimination of all foods is often required. In these cases, patients must be placed on a strict elemental formula for 1 to 3 months to heal the esophagus. Repeat endoscopy with biopsy is often necessary. Several medications have been used including corticosteroids, cromolyn sodium, and leukotriene inhibitors. This review discusses the past year's literature, concentrating on the etiology, diagnosis, and treatment of EE in both children and adults.

Eosinophilic esophagitis in children and adults

Children with eosinophilic esophagitis, an isolated, severe esophageal eosinophilia, present with symptoms similar to gastroesophageal reflux but do not experience response to aggressive antireflux therapy. Increasingly, eosinophilic esophagitis is considered to be a separate entity from reflux disease. Current theory suggests that the former may be caused by cell-mediated food hypersensitivity or may be a subset of eosinophilic gastroenteritis. Reports support the efficacy of dietary restriction or corticosteroid therapy. Additional research is needed to determine etiology, allow earlier clinical recognition, and improve treatment.

Eosinophilic esophagitis

Since Kelly's article appeared in press in 1995, EoE has become an increasingly recognized body. While isolated case reports suggesting EoE have been printed in the adult literature since 1977, many more reports have been published in the pediatric literature over the past 7 years. Recently, [table: see text] several excellent reviews have been written on the subject of EoE [2,25,59,60]. These reviews coupled with the past reports and increasing incidence of EoE provide a sound background for further research on the etiology, epidemiology and treatment of EoE.

Famotidine for infant gastro-oesophageal reflux: a multi-centre, randomized, placebo-controlled, withdrawal trial

BACKGROUND

Gastro-oesophageal reflux afflicts up to 7% of all infants. Histamine-2 receptor antagonists are the most commonly prescribed medications for this disorder, but few controlled studies support this practice.

AIM

To evaluate the safety and efficacy of famotidine for infant gastro-oesophageal reflux disease.

METHODS

Thirty-five infants, 1.3-10.5 months of age, entered an 8-week, multi-centre, randomized, placebo-controlled, two-phase trial: first 4 weeks, observer-blind comparison of famotidine 0.5 mg/kg and famotidine 1.0 mg/kg; second 4 weeks, double-blind withdrawal comparison (safety and efficacy) of each dose with placebo.

RESULTS

No serious adverse events were reported. Eleven patients had 16 non-serious, possibly drug-related adverse experiences: 6 patients with agitation or irritability (manifested as head-rubbing in two), 3 patients with somnolence, 2 patients with anorexia, 2 with headache, 1 patient with vomiting, 1 patient with hiccups, and 1 patient with candidiasis. Of the 35 infants, 27 completed Part I. There were significant score improvements for famotidine 0.5 mg/kg in regurgitation frequency (P = 0.04), and for famotidine 1.0 mg/kg in crying time (P = 0.027) and regurgitation frequency (P = 0.004) and volume (P = 0.01). Eight infants completed Part II on double-blind treatment, which was insufficient for meaningful comparisons.

CONCLUSIONS

Histamine-2 receptor antagonists may cause agitation and headache in infants. A possibly efficacious famotidine dose for infants is 0.5 mg/kg (frequency adjusted for age). As 1.0 mg/kg may be more efficacious in some, the dosage may require individualization based on response. Further sizeable placebo-controlled evaluations of histamine-2 receptor antagonists in infants with gastro-oesophageal reflux disease are warranted.

Elemental diet is an effective treatment for eosinophilic esophagitis in children and adolescents

OBJECTIVE

Eosinophilic esophagitis (EoE), a disorder characterized by eosinophilic infiltration of the esophageal mucosa, has been defined in large part through published case reports and series leading to ambiguity in both diagnostic and treatment options. Corticosteroids, cromolyn, and elemental diet have all been reported as successful treatments for EoE. In this study, we sought to accurately define a population of patients with EoE and then assess their response to elemental diet.

METHODS

A series of patients with chronic symptoms of gastroesophageal reflux disease and an isolated esophageal eosinophilia on esophagogastroduodenoscopy (EGD) were identified. Therapy with a proton pump inhibitor was instituted for 3 months, followed by repeat EGD when symptoms persisted. A 24-h pH probe study was performed, and those with significantly abnormal studies were excluded. The remaining patients were diagnosed with EoE and placed on an elemental diet for 1 month, followed by a repeat EGD.

RESULTS

Of 346 patients with chronic gastroesophageal reflux disease symptoms and eosinophils on esophageal biopsy, 51 (14.7%) were ultimately diagnosed with EoE. There was significant improvement in vomiting, abdominal pain, and dysphagia after the elemental diet. The median number of esophageal eosinophils per high-powered field (HPF) decreased from 33.7 before the diet to 1.0 after the diet (p <0.01). The average time to clinical improvement was 8.5 days.

CONCLUSIONS

Elemental diet resulted in striking improvement in both symptoms and histologic evidence of disease in children and adolescents with EoE, as identified by strict diagnostic criteria.

The use of skin prick tests and patch tests to identify causative foods in eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis is a disease entity in which patients have (1) elevated eosinophils on esophageal biopsy and (2) symptoms of gastroesophageal reflux. The symptoms do not improve on aggressive acid blockade but do improve on elimination diet or corticosteroid treatment, which tentatively links food allergies to this disorder.

OBJECTIVE

The purpose of this study was to identify potential food antigens in eosinophilic esophagitis.

METHODS

Patients with eosinophilic esophagitis were identified by biopsy. Potential food antigens were identified prospectively by skin prick testing and patch testing, which were performed through use of standard methods. Atopic tendencies, demographics, and potential food allergies were identified. Repeat esophageal biopsies were reviewed when possible.

RESULTS

A total of 26 patients (22 male, 4 female) with a biopsied-confirmed diagnosis of eosinophilic esophagitis underwent both skin prick testing and patch testing to identify potential causative foods. Milk and egg were the most common positive foods with skin prick testing. Wheat was the most common positive food with patch testing. The patients were advised to avoid positive foods as identified by skin prick testing and patch testing. In all, 18 patients had resolution of their symptoms, 6 patients had partial improvement, and 2 were lost to follow-up. Overall, after intervention, esophageal eosinophil counts improved from 55.8 to 8.4 eosinophils per high-power field. The foods most commonly identified by patients as causing symptoms were milk and egg.

CONCLUSION

The combination of skin prick testing and patch testing can identify potential causative foods that might contribute to the pathogenesis of eosinophilic esophagitis.

Sedation in pediatric endoscopy

The increase in diagnostic, radiologic, and minor surgical procedures performed on pediatric patients outside of the traditional surgical suite setting has resulted in a marked increase in the use of conscious sedation. Not long ago, pediatric gastroenterologists were reticent about using intravenous sedation for pediatric endoscopy. With increased experience, careful screening, and the specialization of pediatric gastroenterology, however, endoscopy can now be performed safely with intravenous sedation on almost all patients.

Up-regulation of glutathione S-transferase activity in enterocytes of young children

The relationship between age and busulfan apparent oral clearance (Cl/F) expressed relative to adjusted ideal body weight and body surface area (bsa) was evaluated in 135 children aged 0 to 16 years undergoing hematopoietic stem cell transplantation for various disorders. Busulfan plasma levels were measured by gas chromatography-mass spectrometry after the first daily dose of the 4-day dosing regimen. Cl/F expressed relative to adjusted ideal body weight (ml/min/kg) and bsa (ml/min/m(2)) was lower in 9- to 16-year-old (y.o.) compared with 0- to 4-y.o. children (49 and 30%; p<.001). We hypothesized that the greater busulfan Cl/F observed in young children was in part due to enhanced (first-pass intestinal) metabolism. Busulfan conjugation rate was compared in incubations with human small intestinal biopsy specimens from healthy young (1- to 3-y.o.) and older (9- to 17-y.o.) children. Villin content in biopsy specimens was determined by Western blot and busulfan conjugation rate was expressed relative to villin content to control for differences in epithelial cell content in pinch biopsies. Intestinal biopsy specimens from young children had a 77% higher busulfan conjugation rate (p =.037) compared with older children. We have previously shown that glutathione-S-transferase (GST) A1-1 is the major isoform involved in busulfan conjugation, and that this enzyme is expressed uniformly along the length of adult small intestine. Thus, the greater busulfan conjugation activity in intestinal biopsies of the young children was most likely due to enhanced GSTA1-1 expression. We conclude that age dependence in busulfan Cl/F appears to result at least in part from enhanced intestinal GSTA1-1 expression in young children.

Eosinophilic esophagitis: A subset of eosinophilic gastroenteritis

Eosinophilic gastroenteritis (EG) was first described over 50 years ago. Despite its long history, it remains an ill-defined and poorly understood entity. EG can present in a number of ways, none of which are exclusive to the disorder. EG has features of allergy and immune dysregulation but does not clearly fit into the category of allergic or immune disorder. While EG has been reported to affect all locations and layers of the gastrointestinal tract, the vast majority of reported cases have demonstrated mucosal involvement of the gastric antrum and small intestine in addition to disease activity of other locations of the gastrointestinal tract. Recently, several reports have identified a disease consisting of an isolated esophageal eosinophilia. Eosinophilic esophagitis (EE), also known as primary eosinophilic esophagitis or idiopathic eosinophilic esophagitis, occurs in adults and in children and represents a subset of EG with an isolated severe esophageal eosinophilia. Patients with EE present with symptoms similar to those of gastroesophageal reflux but are unresponsive to antireflux medication. Reports have demonstrated that patients with EE respond to either dietary restriction or corticosteroids.

Efficacy and safety of lovastatin in adolescent males with heterozygous familial hypercholesterolemia: a randomized controlled trial

CONTEXT

Heterozygous familial hypercholesterolemia (HeFH) is a common disorder associated with early coronary artery disease, especially in men. The age at which drug therapy should be started is still controversial, as is the use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins).

OBJECTIVE

To assess the lipid-lowering efficacy, biochemical safety, and effect on growth and sexual development of lovastatin in adolescent boys with HeFH.

DESIGN

One-year, double-blind, placebo-controlled, balanced, 2-period, 2-arm randomized trial. In the first period (24 weeks), lovastatin was increased at 8 and 16 weeks and the dosage remained stable during the second period (24 weeks). The study was conducted between 1990 and 1994.

SETTING

Fourteen pediatric outpatient clinics in the United States and Finland.

PATIENTS

Boys aged 10 to 17 years with HeFH. Of 132 randomized subjects (67 intervention, 65 placebo), 122 (63 intervention, 59 placebo) and 110 (61 intervention, 49 placebo) completed the first and second periods, respectively.

INTERVENTION

Lovastatin, starting at 10 mg/d, with a forced titration at 8 and 16 weeks to 20 and 40 mg/d, respectively, or placebo.

MAIN OUTCOME MEASURES

The primary efficacy outcome measure was low-density lipoprotein cholesterol (LDL-C). Primary safety measures were growth and sexual development.

RESULTS

Compared with placebo, LDL-C levels of patients receiving lovastatin decreased significantly (P<.001) by 17%, 24%, and 27% receiving dosages of 10, 20, and 40 mg/d, respectively, and remained 25 % lower than baseline at 48 weeks. Growth and sexual maturation assessed by Tanner staging and testicular volume were not significantly different between the lovastatin and placebo groups at 24 weeks (P = .85) and 48 weeks (P = .33); neither were serum hormone levels or biochemical parameters of nutrition. However, the study was underpowered to detect significant differences in safety parameters. Serum vitamin E levels were reduced with lovastatin treatment consistent with reductions in LDL-C, the major carrier of vitamin E in the circulation.

CONCLUSIONS

This study in adolescent boys with HeFH confirmed the LDL-C-reducing effectiveness of lovastatin. Comprehensive clinical and biochemical data on growth, hormonal, and nutritional status indicated no significant differences between lovastatin and placebo over 48 weeks, although further study is required.

Placebo-controlled trial assessing the use of oral midazolam as a premedication to conscious sedation for pediatric endoscopy

BACKGROUND

This study was performed to evaluate the effect of midazolam, as premedication before intravenous conscious sedation, on preprocedural, procedural, and post-procedural patient comfort and anxiety in children undergoing endoscopy.

METHODS

A placebo-controlled, double-blind, randomized study was conducted in 123 children (age 7.75 +/- 4.46 years, 56% male) using oral midazolam (0.5 mg/kg, maximum 20 mg) as a premedication before insertion of an intravenous access device (i.v.) and upper endoscopy. Patients were evaluated with regard to changes in vital signs, level of sedation during i.v. placement, level of pre- and post-procedure conscious sedation, ease of separation from parents, ease and duration of procedure, recovery time, and amnesia to objects shown before i.v. placement and immediately before the start of the procedure.

RESULTS

A significant difference was noted in the study group for the following parameters: level of sedation for i.v. placement (p < 0.0001), pre-procedural sedation (p < 0.001), ease of i.v. insertion (p < 0.003), ease of separation from parents (p = 0.022), and ease of the nursing personnel's ability to monitor the patient during the procedure (p = 0.0012). The patient's amnesia to an object shown immediately before beginning the endoscopy was increased (p < 0.001). Patients and parents were also more satisfied with the procedure process (p < 0.05). No significant difference was noted with regard to the length or performance of the procedure or recovery time or in the dose of i.v. medication required for successful completion of the endoscopy.

CONCLUSION

Oral midazolam is an effective and safe premedication for children undergoing upper endoscopy and should be used in all anxious children and in patients previously judged to be difficult to sedate.

Primary eosinophilic esophagitis in children: successful treatment with oral corticosteroids

BACKGROUND

The histologic appearance of esophageal eosinophils has been correlated with esophagitis and gastroesophageal reflux disease in children. Esophageal eosinophilia that persists despite traditional antireflux therapy may not represent treatment failure, but instead may portray early eosinophilic gastroenteritis or allergic esophagitis. In this study, a series of pediatric patients with severe esophageal eosinophilia who were unresponsive to aggressive antireflux therapy were examined and their clinical and histologic response to oral corticosteroid therapy assessed.

METHODS

Of 1809 patients evaluated prospectively over 2.5 years for symptoms of gastroesophageal reflux, 20 had persistent symptoms and esophageal eosinophilia, despite aggressive therapy with omeprazole and cisapride. These patients were treated with 1.5 mg/kg oral methylprednisolone per day, divided into twice-daily doses for 4 weeks. All patients underwent clinical, laboratory, and histologic evaluation before and after treatment.

RESULTS

Histologic findings in examination of specimens obtained in pretreatment esophageal biopsies in children with primary eosinophilic esophagitis indicated significantly greater eosinophilia (34.2+/-9.6 eosinophils/high-power field [HPF]) compared with that in children with gastroesophageal reflux disease who responded to medical therapy (2.26+/-1.16 eosinophils/HPF; p < 0.001). After corticosteroid therapy, all but one patient with primary eosinophilic esophagitis had dramatic clinical improvement, supported by histologic examination (1.5 +/-0.9 eosinophils/HPF, p < 0.0001).

CONCLUSIONS

Pediatric patients in a series with marked esophageal eosinophilia and chronic symptoms of gastroesophageal reflux disease unresponsive to aggressive medical antire-flux therapy had both clinical and histologic improvement after oral corticosteroid therapy.

Duodenitis in children: correlation of radiologic findings with endoscopic and pathologic findings

PURPOSE

To determine the accuracy of barium studies in the diagnosis of duodenitis in children.

MATERIALS AND METHODS

Seventy-five children (45 boys and 30 girls; mean age, 9 years) underwent upper gastrointestinal (GI) examinations. Twenty-four of the children had biopsy-proved duodenitis, and 51 were healthy control subjects. Radiologic findings were reviewed by two experienced, blinded observers and correlated with endoscopic and histologic results. Duodenal mucosal-fold thickness was measured on spot radiographs (20% magnification), and the extent of disease was evaluated.

RESULTS

Of 15 children with mild duodenitis, 13 had normal radiologic findings and 11 had normal findings at esophagogastroduodenoscopy. Of nine children with severe duodenitis, all had friability or ulceration at endoscopy and mucosal-fold thickening of greater than or equal to 4 mm (> or = 3 mm in one infant aged less than 1 year) at upper GI examination. Mucosal-fold thickening was diffuse in patients with celiac, autoimmune, and adenovirus disease and was proximal in patients with peptic ulcer and Crohn disease. Of 51 control subjects, 50 had normal radiologic results, while 47 had normal endoscopic results. The sensitivity of upper GI examination for mild and severe duodenitis combined was 46% with a specificity of 98%, whereas endoscopy had a sensitivity of 54% and specificity of 92%.

CONCLUSION

Mucosal-fold thickening was a specific sign of duodenitis in children and should be investigated. Upper GI examination yielded results similar to those at endoscopy.

Pediatric cholesterol screening: missed opportunities

The current recommendations for childhood cholesterol screening include screening children in whom 1) a parent/grandparent has premature heart or vascular disease or died suddenly; 2) a parent has an abnormal lipid profile; 3) the family history is unobtainable. Over a 3-year period, 256 children referred for hypercholesterolemia were evaluated for heritable hyperlipidemia. We reviewed their family histories and obtained lipoprotein profiles of all of their immediate family members. Of these families, 89 parents had unsuspected hypercholesterolemia of whom 38, whose average age was 36 years, died of a myocardial infarction. In addition, 83 children with no family history of premature coronary artery disease or hypercholesterolemia, were diagnosed with inherited hyperlipidemia (25 with hetrozygous familial hypercholesterolemia, and 58 with familial combined hyperlipidemia). Thus, many adults have no awareness of hyperlipidemia prior to a fatal heart attack, nor of their children as having hyperlipidemia, and a large percentage of children with inherited hyperlipidemia would not have been diagnosed if all of their immediate family members (parents and siblings) had not been screened for a complete lipid profile. These results suggest that in addition to screening, all family members of hypercholesterolemic children, pediatricians and family practitioners should urge parents who may be unaware of their cholesterol levels or have no knowledge of their family history to undergo cholesterol screening in order to comply with NCEP guidelines calling for serum cholesterol measurements in all adults above the age of twenty.

Failed Nissen fundoplication in two patients who had persistent vomiting and eosinophilic esophagitis

The following report describes two patients who had chronic symptoms of gastroesophageal reflux and persistent histological esophagitis, despite aggressive medical antireflux therapy, who continued to have esophagitis and remained symptomatic post antireflux surgery (Nissen fundoplication). Both patients demonstrated a severe eosinophilic esophagitis with normal gastric and duodenal histology before and after surgery. Postoperatively, each received the diagnosis of allergic enteritis and both responded clinically and histologically to oral corticosteroids and an elemental diet.

Endoscopic findings in hypertrophic pyloric stenosis: appearance in classic and evolving disease

BACKGROUND

Hypertrophic pyloric stenosis (HPS) is the most common abdominal surgical disorder in infants. Although the majority of cases are diagnosed by ultrasound, equivocal cases may require endoscopy. This study was performed to assess the various endoscopic appearances of HPS in infants.

METHODS

A prospective study comparing the endoscopic appearance of the antrum and pylorus of 18 children with HPS to 21 children in a normal control group.

RESULTS

Antral or pyloric mucosal hypertrophy was visualized endoscopically in all 18 study patients. The degree of mucosal thickening varied depending on the age of presentation and duration of symptoms. Antral fold hypertrophy was first noted at 10 days of age, and in the oldest patient (4 months of age) a pyloric mass was noted. By comparison, 21 control infants had no evidence of antral or pyloric narrowing or mucosal thickening.

CONCLUSIONS

Upper endoscopy can be a valuable adjunctive diagnostic tool in select cases of HPS when imaging tests are inconclusive or when infants present with clinical symptoms outside the typical age-time frame for HPS. Because HPS may evolve over time, it is important that the endoscopist recognize the different appearances of HPS.

Gastric fluid volume in infants for pyloromyotomy

PURPOSE

To quantify gastric fluid volumes in infants with pyloric stenosis presenting for pyloromyotomy and to demonstrate endoscopically the efficacy of blind aspiration for gastric fluid recovery. We hypothesized that previous diagnostic contrast studies, preoperative nasogastric suction, and fasting interval would not affect these volumes.

METHODS

Seventy-five infants scheduled for pyloromyotomy were given atropine before induction of anaesthesia. For those who had undergone preoperative nasogastric suction, the nasogastric tube was aspirated and removed. A 14 F multiorificed orogastric catheter was blindly passed to aspirate gastric fluid for measurement. Following tracheal intubation, 15/75 subjects underwent gastroscopy to measure residual gastric fluid.

RESULTS

Gastric fluid volume removed by blind aspiration averaged 4.8 +/- 4.3 ml.kg-1 with 83% of patients having > 1.25 ml.kg-1. Although 14 of the 15 patients evaluated by endoscope had < or = 1 ml residual gastric fluid, one had 1.8 ml.kg-1. Recovery of total gastric fluid volume by blind aspiration averaged 96 +/- 7%. The large gastric fluid volumes were independent of a history of barium study, preoperative nasogastric suction, and fasting interval.

CONCLUSION

Infants with pyloric stenosis have large gastric fluid volumes which are not substantially reduced by preoperative nasogastric suction. Blind aspiration of gastric contents prior to induction of anaesthesia provides a reliable estimate of total gastric fluid for most of these infants, although the occasional infant may retain a small amount of gastric fluid. The clinical importance of such a residual volume is uncertain.

Gastric fluid measurement by blind aspiration in paediatric patients: a gastroscopic evaluation

PURPOSE

Numerous investigators have estimated gastric fluid volume using blind aspiration through multi-orificed catheters, but none have confirmed the validity of this technique in infants and children. We sought to validate the accuracy of this technique in a fasted paediatric population by using gastroscopy. Data from several studies were then combined to generate a gastric fluid volume frequency distribution for healthy paediatric patients fasted for surgery.

METHODS

This is a prospective study of 17 patients aged six months to 11 yr who underwent elective upper endoscopy at a paediatric teaching hospital. Gastric contents were aspirated blindly with a syringe and a 16 or 18F multi-orificed orogastric tube, and the volume of gastric contents removed in the supine and decubitus positions was measured. Residual gastric fluid was aspirated using an endoscope. Data from 611 infants and children enrolled in previously published studies utilizing the same blind aspiration technique were pooled and a gastric fluid volume frequency distribution was created.

RESULTS

Blind aspiration removed 97 +/- 8% of the total gastric fluid volume. In 661 children presenting for elective surgery, the gastric fluid volume was 0.40 +/- 0.45 ml.kg-1. Median volume was 0.27 ml.kg-1, with the 95%ile at 1.25 ml.kg-1 and an upper limit of 4.1 ml.kg-1.

CONCLUSION

Blind aspiration of gastric contents accurately estimates gastric fluid volume for paediatric patients fasted for surgery. Population estimates for gastric fluid volume in otherwise healthy fasted paediatric patients are shown.

Pediatric enteral access center: a multidisciplinary approach

The need for enteral access and gastrostomy placement in children has increased dramatically over the past several years. In the following article, we present a case report of a typical patient undergoing evaluation for enteral nutrition and enteral access. Following the case report, we describe our newly formed Pediatric Enteral Access Program including patient selection, the method of gastrostomy placement, risks and benefits, cost analysis, and follow-up of this ever-increasing population of children.