Diagnosing eosinophilic colitis: histopathological pattern or nosological entity?

The efficacy of JAK inhibitors in adult eosinophilic colitis with atopic dermatitis; four cases report

We herein present four cases of Eosinophilic colitis (EoC) in adult patients who were successfully treated with a Janus kinase (JAK) inhibitor. Case 1 is a 23-year-old female who was treated with baricitinib (BAR, 4 mg, once a day) for atopic dermatitis (AD). Colonoscopy (CS) initially did not reveal any significant abnormalities. However, she underwent another CS when she underwent a food challenge test involving wheat without baricitinib medication. During this procedure, the CS subsequently leading to her diagnosis of EoC based on eosinophil infiltration. Case 2 is a 26-year-old man whereas Case 3 is a 40-year-old man. Both patients were started on upadacitinib (UPA, 15 mg, once daily) for the treatment of AD. Their abdominal symptoms improved, and colonic histology revealed the disappearance of eosinophils. Case 4, on the other hand, is a 29-year-old woman who was also started on UPA (15 mg, once daily). Her skin lesions and abdominal symptoms also improved within 2 weeks. To the best of our knowledge, this is the first novel clinical observational case report on the efficacy of JAK inhibitors in treating adult patients with both EoC and AD.

Clinical significance of direct fast scarlet staining on the diagnosis of eosinophilic colitis: A comparative study focusing on the eosinophil degranulation in colonic mucosal tissue

This study aimed to validate the DFS (direct fast scarlet) staining in the diagnosis of EC (eosinophilic colitis). The study included 50 patients with EC and 60 with control colons. Among the 60 control samples, 39 and 21 were collected from the ascending and descending colons, respectively. We compared the median number of eosinophils and frequency of eosinophil degranulation by HE (hematoxylin and eosin) and DFS staining between the EC and control groups. In the right hemi-colon, eosinophil count by HE was useful in distinguishing between EC and control (41.5 vs. 26.0 cells/HPF, p < 0.001), but the ideal cutoff value is 27.5 cells/HPF (high-power field). However, this method is not useful in the left hemi-colon (12.5 vs. 13.0 cells/HPF, p = 0.990). The presence of degranulation by DFS allows us to distinguish between the groups even in the left hemi-colon (58% vs. 5%, p < 0.001). DFS staining also enabled a more accurate determination of degranulation than HE. According to the current standard to diagnose EC (count by HE staining ≥20 cells/HPF), mucosal sampling from left hemi-colon is problematic since the number of eosinophils could not be increased even in EC. Determination of degranulated eosinophils by DFS may potentiate the diagnostic performance even in such conditions.

Clinical and atopic features of patients with primary eosinophilic colitis: an Italian multicentre study

Eosinophilic colitis (EC) is the rarest among primary eosinophilic gastrointestinal disorders (EGID). EC is underdiagnosed due to its blurred and proteiform clinical manifestations. To explore the clinical and atopic characteristic of EC adult patients, the diagnostic delay, and relapse-associated factors, by comparison with patients with eosinophilic esophagitis (EoE) and irritable bowel syndrome (IBS). EC patients followed-up at four clinics were included, and clinical, histopathological, and laboratory data were retrieved. As control groups, age-matched patients with EoE and IBS were recruited. Allergy tests included skin prick test and serum specific IgE. Diagnostic delay was assessed. Overall, data from 73 patients were retrieved, including 40 with EC (median age 39 years IQR 22.5-59, F:M 2.1:1), 12 with EoE (F:M ratio: 1:5), and 21 with IBS (F:M ratio: 1:0.9). The most common features in EC patients were female sex (67.5%), atopy (77.5%), abdominal pain/distention (70%), diarrhoea (77.5%), and faecal calprotectin elevation (22.5%). Blood eosinophils were elevated in EoE, but not in EC (p < 0.001), while ECP did not differ across the three groups (p = 0.4). The frequency of allergen sensitization reached 25% of patients. Several frequent pan-allergens for this region were present. The overall diagnostic delay was 10 months (IQR 4-15). Factors contributing to a greater diagnostic delay were atopy, weight loss, and a previous misdiagnosis. EC is mostly a diagnosis of exclusion, burdened by a substantial diagnostic delay. In female patients the presence of allergen sensitization, abdominal symptoms and faecal calprotectin elevation should raise the suspicion of EC.

The Relationship between Eosinophil Density in the Colonic Mucosa and Eosinophil Blood Count in Children: A Cross-Sectional Study

Eosinophils are found in the mucosa of the healthy gastrointestinal tract, but they also often accompany gastrointestinal diseases. We hypothesized that a positive correlation exists between blood eosinophil count and colonic eosinophil mucosal density in children. Electronic health records regarding 181 colonoscopies, performed with biopsy in the years 2019-2022, were screened for information on blood and colonic eosinophil count, age, sex, diagnoses, weight, height, white blood cell (WBC) count, serum C-reactive protein (CRP), and total IgE concentration. The median age (IQR) of the 107 included children (109 colonoscopies) was 12.4 years (8.1-15.5); 32 presented with blood eosinophilia (29.3%). The median eosinophil density/high-power field in the colonic mucosa was 22.5 (9-31). We found a weak correlation between colonic mucosal eosinophil density and blood eosinophil count (r = 0.295, 95% CI 0.108-0.462, p = 0.0018). This association was more pronounced in patients with elevated CRP (r = 0.529, 95% CI 0.167-0.766, p = 0.0054) and older than 12.4 years (r = 0.448, 95% CI 0.197-0.644, p = 0.00068). Peripheral blood eosinophilia might hint at increased mucosal colonic eosinophil density, especially in older children and in the presence of systemic inflammation. However, it seems unlikely that blood and colonic eosinophilia are strongly linked in younger children. Studies in adults are warranted.

Duodenal Eosinophils and Mast Cells in Functional Dyspepsia: A Systematic Review and Meta-Analysis of Case-Control Studies

BACKGROUND & AIMS

This study explored the link between duodenal eosinophils and mast cells in patients with functional dyspepsia (FD).

METHODS

MEDLINE (PubMed) and Embase electronic databases were searched until June 2021 for case-control studies reporting duodenal eosinophils and mast cells in FD. Pooled standardized mean difference (SMD), odds ratio, and 95% CIs of duodenal eosinophils and mast cells in FD patients and controls were calculated, using a random-effects model.

RESULTS

Twenty-two case-control studies with 1108 FD patients and 893 controls were identified. Duodenal eosinophils (SMD, 1.29; 95% CI, 0.85-1.73; P = .0001) and mast cells (SMD, 2.11; 95% CI, 1.14-3.07; P = .0001) were increased in FD patients compared with controls. Substantial heterogeneity was found (I2 = 93.61, P = .0001; and I2 = 96.69, P = .0001, respectively) and visual inspection of funnel plots confirmed publication bias. Degranulation of duodenal eosinophils was significantly higher in FD patients compared with controls (odds ratio, 3.78; 95% CI, 6.76-4.48; P = .0001), without statistically significant heterogeneity. We conducted a sensitivity analysis for duodenal eosinophils, by including only high-quality studies, and the results remained unchanged (SMD, 1.73; 95% CI, 1.06-2.40; P = .0001), with substantial heterogeneity. Postinfectious FD patients had increased duodenal eosinophils compared with controls (SMD, 3.91; 95% CI, 1.32-6.51; P = .001) and FD patients without any history of infection (SMD, 1.42; 95% CI, 0.88-1.96; P = .001). Helicobacter pylori-negative FD patients had significantly higher duodenal eosinophils compared with controls (SMD, 3.98; 95% CI, 2.13-5.84; P = .0001), with substantial heterogeneity. No significant difference in duodenal eosinophils was seen according to FD subtypes.

CONCLUSIONS

This meta-analysis suggests a link between duodenal microinflammation and FD. However, the quality of evidence is very low, largely owing to the unexplained heterogeneity and serious risk of publication bias in all comparative analyses. Thus, causality remains uncertain and further studies are required.

Pan-Gastrointestinal Tract Mucosal Pathologies in Patients with Celiac Disease with the Demonstration of IgA Anti-Transglutaminase Mucosal Deposits: A Case-Control Study

BACKGROUND

While celiac disease (CeD) is considered to affect primarily the small intestine, pathological changes in other parts of the gastrointestinal tract (GIT) are also known to occur. IgA anti-tissue transglutaminase-2 antibody (anti-TG2 Ab) deposits at the site of involvement is one of the methods to establish CeD-related tissue pathology.

AIMS

To explore the utility of IgA anti-TG2 Ab deposits in pan-gastrointestinal mucosal biopsies as evidence of CeD-related pathologies.

METHODS

Forty-two treatment-naive patients with CeD and 45 patients with irritable bowel syndrome were included as cases and controls, respectively. Mucosal biopsies were collected from the esophagus, stomach, duodenum, and rectosigmoid regions at baseline from cases and controls, and additionally after 6-months of gluten-free diet in cases. All biopsies were evaluated for histological changes and subjected to dual-color immunohistochemical staining for identifying IgA anti-TG2 Ab deposits.

RESULTS

Significantly higher number of patients with CeD had lymphocytic esophagitis (9.7% vs. 0%, P = 0.05), lymphocytic gastritis (35% vs. 8.8%, P < 0.01) and lymphocytic colitis (17.4% vs. 0%, P < 0.05) than that in controls. IgA anti-TG2 Ab deposits were observed in significantly more numbers in esophagus (30.9% vs. 6%, P < 0.001), stomach (62.2% vs. 9.3%, P < 0.01), duodenum (88.5% vs. 0%, P < 0.001) and rectum (17.4% vs. 0%, P < 0.05) than that in controls. There was a decline, but not statistically significant, in severity of lymphocytosis and intensity of IgA anti-TG2 Ab deposits in follow-up biopsies.

CONCLUSION

Significantly higher number of patients with CeD had evidence of lymphocytic infiltration and IgA anti-TG2 deposits along GIT suggesting that CeD affects other parts of GIT.

Pathologist's approach to paediatric and neonatal eosinophilic gastrointestinal disorders

Children are not simply miniature adults. The evaluation of their gastrointestinal disorders is therefore different from that in full-grown adults and requires a particular clinical/pathologic approach. Different studies have tried to assess the normal eosinophil distribution in the gastrointestinal tract in adults while very few studies have investigated the paediatric population, consequently complicating the pathologist's ability in identifying an abnormal number of eosinophils in this setting of patients. When evaluating gastrointestinal tract biopsies with eosinophilia, eosinophilic count must be considered along with other histological features like eosinophil distribution in the gastrointestinal wall, their degranulation, cryptitis and crypt abscesses, other accompanying inflammatory cells, apoptotic bodies, foreign material or microorganisms; these findings, although rarely specific, may be a useful aid for diagnosis. Reports should not include a diagnosis of primary eosinophilic gastrointestinal disorders (EoGID) if clinical data and test results do not rule out other forms of gastrointestinal eosinophilia. A more descriptive definition like "with eosinophilic pattern" should be favoured over a specific diagnosis of "eosinophilic disorder" in order to avoid potential confusion between different entities.

Histopathological Characterization of Colitis in Captive Western Lowland Gorillas (Gorilla gorilla ssp gorilla)

In captive gorillas, ulcerative colitis is an important cause of morbidity and mortality with no established definitive aetiopathogenesis. The aim of the study was to characterize histopathologically colonic lesions in captive western lowland gorillas (Gorilla gorilla ssp gorilla) and to apply the Nancy index, a disease activity scoring system for ulcerative colitis in humans. Colon samples from 21 animals were evaluated on the basis of histopathological characteristics for the diagnosis of inflammatory bowel disease in humans and divided into acute or chronic changes. The most common acute changes included the presence of neutrophils in the lamina propria (17/18; 94%), mucosal and submucosal oedema (12/18; 67%) and crypt abscesses (8/18; 44%). The most common chronic changes were lamina proprial lymphoplasmacytic infiltrates (17/18; 94%) and crypt dilation or distortion (6/18; 33%). Based on the Nancy index, 4/21 (19%) cases were grade 4 (the highest grade), 2/21 (10%) were grade 3, 11/21 (52%) were grade 2 and 4/21 (19%) cases were grade 0. The colonic changes were comparable to the acute phase of ulcerative colitis in humans. No unifying aetiopathogenesis could be identified. The Nancy index proved to be a valuable tool for the standardization of disease grading and established a basis for future studies of gorilla colitis.

Eosinophilic Colitis and Clostridioides difficile Sepsis With Rapid Remission After Antimicrobial Treatment; A Rare Coincidence and Its Pathogenic Implications

Eosinophilic colitis is a rare inflammatory disorder of the digestive tract with chronic evolution and unknown pathophysiological mechanisms. The article describes the case of a 64-year old woman with a history of asthma and hypereosinophilia, who presented to a surgical department for persistent abdominal pain in the past 4 months, weight loss and malabsorption. She was diagnosed with eosinophilic colitis based on the colonoscopic result indicating extensive eosinophilic infiltration of the colonic mucosa correlated with the laboratory data and abdominal CT scan results. Following the colonoscopy, the patient developed fever, hypotension and diarrhea and was transferred to an Infectious Diseases Department with a presumptive diagnosis of abdominal sepsis. Treatment with ertapenem was immediately started. Metronidazole was also added due to a PCR positive stool test for Clostridioides difficile toxins encoding-genes. The patient displayed a rapid remission of the fever and of the intestinal complaints following antibiotic therapy and was discharged after 14 days. During a 3 months follow-up, the patient remained asymptomatic with normal values of laboratory parameters except for a persistent hypereosinophilia. The case outlines two distinguishing features: a histopathologic diagnosis of eosinophilic colitis, a rare diagnosis of a patient with chronic abdominal pain and an unexpected and rapid remission of the eosinophilic colitis following the antibiotic treatment and the restoration of the intestinal eubiosis.

A Pink Herring in the Colon: A Case Report of Eosinophilic Colitis Masking Invasive Adenocarcinoma of the Colon

Eosinophilic colitis is an inflammatory condition in which the wall of the colon becomes infiltrated by eosinophils which stain densely pink on microscopy. It is an uncommon clinical entity which has a long list of differential diagnoses. We present a case of a patient whose biopsy at colonoscopy revealed eosinophilic colitis which led to a delay in the diagnosis and subsequent treatment of colon cancer. A 35-year-old male presented with a six-week history of right lower quadrant abdominal pain associated with diarrhoea and weight loss. Colonoscopy showed an inflamed cecum; computed tomography revealed a small ascitic fluid collection in the right iliac fossa. Biopsy showed eosinophilic colitis, and he was treated conservatively with albendazole and mesalamine. The patient failed to improve over the following month with continued weight loss. A repeat CT scan showed a right iliac fossa mass. A right hemicolectomy was performed with histopathology from the specimen showing mucinous adenocarcinoma. Eosinophilic colitis can mask colon cancer and should be considered a diagnosis of exclusion.

Eosinophilic esophagitis, gastroenteritis, and colitis in a patient with prior parasite exposure

Eosinophilic gastrointestinal disorders (EGID) comprise a spectrum of inflammatory diseases that can affect any segment of the gastrointestinal tract. The pathogenesis of these conditions is complex; differentiating between primary and secondary forms of these disorders can be clinically challenging. We report a case of primary EGID in a patient with remote parasite exposure, whose symptoms were initially attributed to irritable bowel syndrome. Endoscopy revealed the rare finding of EGID involving the entire gastrointestinal tract; symptoms improved with an elimination diet. This case raises the possibility of a link between prior parasite exposure and development of EGID, and underscores the necessity of exploring alternative diagnoses in patients with presumed IBS who present with severe symptoms.

Eosinophil Counts in Mucosal Biopsies of the Ileum and Colon: Interobserver Variance Affects Diagnostic Accuracy

Primary eosinophilic gastroenteritis and colitis (EGE) is a rare entity with unspecific clinical and endoscopic findings. Validated histopathologic criteria for confirming the diagnosis are lacking, because numeric values for normal or elevated concentrations of eosinophils in mucosal biopsies are varying between observers. To quantify this interobserver variance, we had the same set of 30 slides of eosinophilic-rich mucosal biopsies from the ileum and colon systematically reviewed by a panel of six independent pathologists, each with more than a ten-year experience in the field. Using a highly standardized biopsy and slide preparation protocol, we ruled out any influence by the preparation, the patient, the endoscopist, the endoscopes and calipers used, the sampling site, the fixation and staining method, and the microscopic field sizes. Still, all numeric results differed between pathologists up to a factor greater than 30. Calculated positive or negative diagnosis of EGE differed up to a factor greater than 8. A theoretical incidence for EGE calculated from these numbers differed by a factor greater than 1500. We conclude that eosinophil counts in mucosal biopsies from the lower gastrointestinal tract are subject to a very high interobserver variance. Until further research provides objective and validated methods for standardization, all epidemiologic numbers derived from histopathologic findings may have to be questioned. When diagnosing individual patients with EGE, overall morphologic picture together with clinical and endoscopic findings is more important than numeric eosinophil count.

Eosinophil Counts in the Small Intestine and Colon of Children Without Apparent Gastrointestinal Disease: A Meta-analysis

The aim of the current study was to review the available data regarding eosinophil density in healthy tissue specimen originating from lower gastrointestinal segments to support suggested diagnostic cutoffs widely used in clinical practice. A systematic search was performed in 3 different databases. Calculations were made with Comprehensive MetaAnalysis software using random-effects model. Cell number measurements were pooled using the random-effects model and displayed on forest plots. Summary point estimations, 95% confidence intervals (CIs), and 95% prediction intervals (PIs) were calculated. The cumulative mean cell numbers were 8.26 (95% CI 4.71-11.80) with PI of 0-25.32 for the duodenum, 11.52 (95% CI 7.21-15.83) with PI 0-60.64 for the terminal ileum, and 11.10/ high-power field (HPF) (95% CI 9.11-13.09) with PI of 0.96 to 21.23 in the large intestine and the rectum (HPF area = 0.2 mm). Previous studies included control patients with irritable bowel syndrome and functional gastrointestinal disorders. As mucosal eosinophils have a role in their pathomechanism, those patients should have been excluded. A critical point of interpreting reported data is that HPF is relative to the technical parameters of the microscopes; therefore, it is important to report findings in cell/mm. The present meta-analysis does not support the higher (>20) or lower (<10) cutoff values for healthy tissue eosinophil number. In contrast to the esophagus, there is no normal cutoff eosinophil density in the small intestine and the colon. A prospective, multicenter study to establish normal mucosal eosinophil density is clearly needed.

The colon and terminal ileum in patients with ankylosing spondylitis and controls in Bangladesh: a macroscopic and microscopic study

OBJECTIVE

Little is known about gut lesions in AS patients in a developing country, such as Bangladesh.

METHODS

Full colonoscopy, including the terminal ileum, was performed in 60 AS patients and 20 controls, without diarrhoea, to study macroscopic and microscopic lesions.

RESULTS

In the colon, in 60 AS patients 17 macroscopic lesions were found, of which 11 were in the rectum; only one lesion was found in 20 controls. The prevalence of microscopic lesions in the ascending colon, sigmoid colon and rectum was 51, 44 and 50 in patients, respectively, and 13, 9 and 8 in controls. In the terminal ileum, macroscopic and microscopic lesions were seen in 21/56 and 43/56 AS patients, respectively, and in 1/20 and 9/20 controls. In the AS group, macroscopic (38.5 vs 5%, P < 0.01) and microscopic (76.8 vs 45%, P = 0.009) lesions were more frequent than in controls; no IBD was diagnosed. Findings were comparable in the axial AS group (n = 25) and the mainly peripheral group (n = 35). In AS patients, marked eosinophilic infiltration was observed in the ascending colon and sigmoid colon but not in the rectum, and this infiltration was more than in controls. The colonic mucosa in controls was otherwise comparable with western studies. Anaemia was seen in 18/60 cases. No association was found between anaemia or HLA-B27 status and gut lesions.

CONCLUSION

There was an equal percentage of microscopic lesions in the whole gut in AS cases and healthy controls. Previous helminth invasions might have played a role. Lesions differ significantly between AS and controls only in the ileum; therefore, the ileal lesions might be more disease related than the colonic ones.

Eosinophilic Gastrointestinal Disorders Pathology

Eosinophilic gastrointestinal disorders (EGID) are characterized pathologically by excess eosinophils in mucosal biopsies of one or multiple sites in the gastrointestinal (GI) tract, simultaneously or sequentially. Eosinophilic esophagitis (EoE) is the best characterized EGID, and in most patients it is an abnormal immune-mediated response to food antigens. Current recommendations for diagnosis include signs and symptoms of esophageal dysfunction that do not respond to proton-pump inhibitor therapy, and esophageal biopsies that exhibit at least 15 intraepithelial eosinophils in at least one high power field (HPF). Therapy consists of swallowed glucocorticoids or dietary elimination. Eosinophilic gastritis (EG) is the second most common form of EGID, but like all forms of EGID except EoE consensus recommendations for either clinical or pathological diagnosis do not exist. EG may be associated clinically with peripheral blood eosinophilia, hypoalbuminemia, and anemia, and pathologically with marked expansion of lamina propria by dense eosinophilic infiltrates. Eosinophilic enteritis (EE) may be subdivided into eosinophilic duodenitis, eosinophilic jejunitis, and eosinophilic ileitis. Most investigators believe that EE rarely, if ever, exists as a solitary form of EGID and is encountered only in patients who have at least one other affected portion of the GI tract. Eosinophilic colitis (EC) is perhaps the most enigmatic EGID. Distinction of EC from inflammatory bowel disease may be problematic especially in children. Multiple possible etiologies for EGID include hypereosinophilic syndrome, drug reactions, etc. Currently, the only etiology that can be identified histologically is parasitic infestation, if a portion of an invasive parasite is found in mucosal biopsies. This review will provide guidelines for the pathologic diagnosis of the various forms of EGID.

Eosinophilic Enterocolitis: An Exceedingly Rare Entity

Eosinophilic enterocolitis is an exceptionally rare condition with few described cases in the literature, representing the least frequent manifestation of the wide spectrum of eosinophilic gastrointestinal disorders. We describe a case of a young male patient presenting with a panmural form of the disease, manifested by abdominal pain, distention, and watery diarrhea with 4 days of evolution, bowel wall thickening, and ascites. Eosinophilic ascites is probably the most unusual presentation form of this entity. It poses a diagnostic challenge because of its nonspecific symptoms, associated with the absence of standardized histological criteria, hence requiring a high level of suspicion. There is also no consensus regarding treatment: it should be individualized according to the patient's age and severity of symptoms.

Eosinophilic Colitis Masquerading as Malignancy of Colon

Eosinophilic colitis (EC) is a rare part of spectrum of diseases called eosinophilic gastrointestinal disease (EGID). It was found to have bimodal distribution involving neonates and adults in age groups of 30 - 50 with male preponderance. We present this case of a 78-year-old woman who came to the hospital with abdominal pain, hematochezia and unintentional weight loss, and was found to have EC. This case was very unique given the age at presentation and the radiological findings mimicking malignancy. We reviewed the possible etiologies, clinical features, pathology, and treatment of EC along with the review of the literature.

Histologic Correlates of Clinical and Endoscopic Severity in Children Newly Diagnosed With Ulcerative Colitis

To characterize rectal histology in an inception cohort of children newly diagnosed with ulcerative colitis (UC) and to explore its relationship with clinical indices of disease severity. The PROTECT (Predicting Response to Standardized Pediatric Colitis Therapy) Study enrolled children 17 years of age and younger newly diagnosed with UC. Baseline rectal biopsies were evaluated for acute and chronic inflammation, eosinophilic inflammation (peak eosinophil count > 32 eosinophils/high powered field, eosinophilic cryptitis or abscesses), and architectural/nonarchitectural chronic changes. Correlation with clinical indices including Mayo endoscopy subscore and Pediatric Ulcerative Colitis Activity Index was performed. Rectal biopsies from 369 patients (mean age, 12.9±3.1 y, 50% female) were reviewed. Cryptitis was found in 89%, crypt abscesses in 25%, and eosinophilic inflammation in 58%. Crypt distortion/atrophy was present in 98% of specimens. Higher grades of acute and chronic inflammation were associated with the presence of basal plasmacytosis (P<0.0001), basal lymphoid aggregates (P<0.0001), and surface villiform changes (P<0.0001). A severe Mayo endoscopy subscore was most common among those with severe acute and chronic inflammation, although this relationship was not linear. Severe Pediatric Ulcerative Colitis Activity Index scores were associated with the absence of or only mild eosinophilic inflammation (<32 eosinophils/high powered field) (P<0.03) and the presence of surface villiform changes (P<0.005). Acute and chronic inflammation, eosinophilic inflammation and chronic changes are common in children newly diagnosed with UC. The clinical and biological implication of low to absent eosinophilic inflammation and the presence of surface villiform changes requires further study.

Pharmacological treatment of eosinophilic gastrointestinal disorders

INTRODUCTION

Eosinophilic gastrointestinal disorders (EGIDs) are increasingly prevalent chronic inflammatory diseases characterized by eosinophilic infiltration of the gastrointestinal (GI) tract, in the absence of other known causes of eosinophilia.

AREAS COVERED

Clinical management of EGIDs is challenging, as there are currently limited therapeutic options available. The most common EGID is eosinophilic esophagitis (EoE), and rarer forms are eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis. Clinical presentation depends on the affected GI site. Recently duodenal eosinophilia has been recognized to commonly be present in patients with functional dyspepsia. This review will provide an overview of the pathogenesis and therapeutic management of EGIDs, with particular focus on the pharmacological strategies for these conditions. Expert commentary: Despite the considerable progress made in understanding the pathogenesis of EGIDs, there is still an urgent need for the development of specific and effective therapeutic approaches. Therapeutic management protocols are required that are based on rigorous clinical investigation in large prospective controlled trials to better understand the risks, benefits and limitations of each therapy. More well-defined and consistent end-points are also required to assess treatment outcomes, as there has been variability between patient reported outcomes, clinical outcomes, and histological outcomes in the studies to date.

Prevalence of Eosinophilic Gastritis, Gastroenteritis, and Colitis: Estimates From a National Administrative Database

OBJECTIVES

Eosinophilic esophagitis (EoE) is becoming increasingly more common, but the prevalence of other eosinophilic gastrointestinal disorders (EGIDs) is unknown. Our objective was to estimate the prevalence of eosinophilic gastritis, gastroenteritis, and colitis in the United States.

METHODS

We used the IMS Health LifeLink PharMetrics Plus Claims Database, data representative of a US national commercially insured population containing medical and pharmaceutical claims for > 75 million individuals. We restricted our sample to patients ages 0 to 64 with continuous enrollment between July 1, 2009, and June 30, 2011. We identified patients with eosinophilic gastritis, gastroenteritis, and colitis as defined by ≥ 1 instance of the International Classification of Diseases, Ninth Revision codes 535.70, 558.41, and 558.42, respectively. We calculated the prevalence of the codes in the database and then standardized the estimates to the US population by age and sex.

RESULTS

The standardized estimated prevalences of eosinophilic gastritis, gastroenteritis, and colitis were 6.3/100,000, 8.4/100,000, and 3.3/100,000, respectively. The prevalence of eosinophilic gastroenteritis was the highest among children age < 5 years, whereas eosinophilic gastritis was more prevalent among older age groups. We observed no age differences for eosinophilic colitis. Among affected patients, there was a high proportion of coexisting allergic conditions, 38.5% for eosinophilic gastritis, 45.6% for gastroenteritis, and 41.8% for colitis. Concomitant allergic disease was most commonly identified in pediatric patients.

CONCLUSIONS

The prevalence of non-EoE EGIDs remains rare in the United States, with < 50,000 total patients affected. There appears to be a female predominance and a high co-occurrence of atopic comorbidities.

Microscopic colitis (lymphocytic and collagenous), eosinophilic colitis, and celiac disease

Multiple tests are needed to diagnose a patient with noninfectious diarrhea. Some patients will be mistakenly labeled as diarrhea-predominant irritable bowel syndrome (IBS-D) because of nonspecific computed tomographic scans and grossly normal endoscopic findings. It is crucial to understand other less common pathologies to avoid these instances of misdiagnosis. This article focuses on microscopic colitis (MC), eosinophilic colitis (EC), and celiac disease. MC is an inflammatory condition of the colon that presents with two subtypes, only to be differentiated by histology. EC is a rare chronic inflammatory process. Depending on the extent of the disease, it can present with mild diarrhea, malabsorption, or at its worst, cause obstruction and perforation. Celiac disease affects the small bowel, but interestingly can present similarly to colitis. Both MC and EC respond to oral budesonide. Patients with celiac disease improve on gluten-free diets. These treatments are distinctly different from typical IBS-D care plans.