Pericrypt eosinophilic enterocolitis and chronic diarrhea.

An unusual pattern of eosinophilic infiltration around intestinal crypts was detected in mucosal biopsy specimens of 10 patients with chronic diarrhea, half of whom had evidence of systemic connective tissue disease. The median duration of symptoms was 11 months, and no other explanation for diarrhea could be determined in any case. The cellular infiltrate on biopsy specimens was present deep in the mucosa of small and large intestinal specimens, separating crypt bases from the muscularis mucosae and penetrating the latter. Consistent with the microscopic findings, surface mucosal appearance by endoscopy was uniformly normal. These histological features of colonic biopsy specimens were statistically differentiated from those of asymptomatic subjects (n = 8), subjects with diarrhea-predominant irritable bowel syndrome (n = 6), and subjects with collagenous colitis (n = 7) or lymphocytic colitis (n = 5). Diarrhea improved in five of seven subjects treated with oral prednisone or prednisone in conjunction with azathioprine (median follow-up period, 2.2 years). Histological changes on subsequent biopsy specimens correlated closely with symptomatic status. These findings strongly suggest that chronic diarrhea is related to this pericrypt eosinophilic enterocolitis, a pathological lesion often associated with features of systemic connective tissue disease. The disorder appears responsive to corticosteroid therapy in some cases.