Campylobacter Pouchitis Mimicking the Appearance of Crohn's Disease

Gastrointestinal histoplasmosis complicating pediatric Crohn disease: A case report and review of literature

BACKGROUND

Infection with Histoplasma capsulatum (H. capsulatum) can lead to disseminated disease involving the gastrointestinal tract presenting as diffuse abdominal pain and diarrhea which may mimic inflammatory bowel disease (IBD).

CASE SUMMARY

We report a case of 12-year-old boy with presumptive diagnosis of Crohn disease (CD) that presented with several months of abdominal pain, weight loss and bloody diarrhea. Colonoscopy showed patchy moderate inflammation characterized by erythema and numerous pseudopolyps involving the terminal ileum, cecum, and ascending colon. Histologic sections from the colon biopsy revealed diffuse cellular infiltrate within the lamina propria with scattered histiocytic aggregates, and occasional non-necrotizing granulomas. Grocott-Gomori’s Methenamine Silver staining confirmed the presence of numerous yeast forms suggestive of Histoplasma spp., further confirmed with positive urine Histoplasma antigen (6.58 ng/mL, range 0.2-20 ng/mL) and serum immunoglobulin G antibodies to Histoplasma (35.9 EU, range 10.0-80.0 EU). Intravenous amphotericin was administered then transitioned to oral itraconazole. Follow-up computed tomography imaging showed a left lower lung nodule and mesenteric lymphadenopathy consistent with disseminated histoplasmosis infection.

CONCLUSION

Gastrointestinal involvement with H. capsulatum with no accompanying respiratory symptoms is exceedingly rare and recognition is often delayed due to the overlapping clinical manifestations of IBD. This case illustrates the importance of excluding infectious etiologies in patients with “biopsy-proven” CD prior to initiating immunosuppressive therapies. Communication between clinicians and pathologists is crucial as blood cultures and antigen testing are key studies that should be performed in all suspected cases of histoplasmosis to avoid misdiagnosis and inappropriate treatment.

Gastrointestinal Histoplasmosis Mimicking Crohn's Disease

Disseminated histoplasmosis is a life-threatening disease usually seen in immunocompromised patients living in endemic areas. We present an apparently immunocompetent patient with gastrointestinal histoplasmosis who was initially diagnosed with biopsy-proven Crohn's disease. Following discontinuation of anti-inflammatory drugs and institution of antifungal therapy, his gastrointestinal illness completely improved. Specific fungal staining should be routinely included in histopathologic assessment of tissue specimens diagnosed as Crohn's disease.

Value of routine stool testing for pathogenic bacteria in the evaluation of symptomatic patients with ileal pouches

BACKGROUND

In symptomatic patients with an ileal pouch, stool studies are often sent to diagnose enteric pathogens. Aim of this study is to find the value of routine stool studies in the evaluation of symptomatic patients and the clinical implications of such pathogens in patients with ileal pouches.

METHODS

Consecutive ileal pouch-anal anastomosis (IPAA) patients who had stool tests out of a 2283-case registry from 2002 to 2015 were included in the study. Patients with positive stool cultures were compared with controls (symptomatic without positive stool culture) in a 1:4 ratio. Response to antibiotic therapy, recurrence rate and rate of hospitalization at 1 and 3 months were assessed.

RESULTS

A total of 643 (28%) had stool cultures done and only 1.7% (11/643) were found to be positive for stool cultures. Campylobacter spp. (45%) was the most common pathogen followed by Aeromonas spp. (36%). Non-smokers and patients without any antibiotic use in the last 3 months were found to have higher prevalence of positive stool cultures than controls (p < 0.001 and p = 0.023). Patients with pathogenic bacteria were found to have a higher risk of acute kidney injury (27.3% vs 4.5%, p = 0.049), hospitalization within 3 months of initial stool testing (36.4% vs 6.8%, p = 0.009) and mortality (18.2% vs 0%, p = 0.040). However, there were no statistically significant differences in the clinical outcomes in patients with positive stool cultures who received pathogen-directed therapy.

CONCLUSIONS

We found that the yield of stool tests for bacterial pathogens in symptomatic pouch patients was extremely low and the treatment of detected pathogens had a minimum impact on the disease course of pouchitis. The clinical utility of routine stool culture in those patients warrants further study.