Eosinophilic colitis: A clinical review

Eosinophilic colitis is a rare entity characterized by the presence of a high eosinophilic infiltrate into the colonic wall in symptomatic patients, more often presenting with abdominal pain or diarrhea. These characteristics distinguish eosinophilic colitis from primary colonic eosinophilia, in which patients are asymptomatic. Primary colonic eosinophilia does not need any therapy, while eosinophilic colitis requires a strict treatment, similar to that of the more codified chronic intestinal inflammatory diseases. To date the lack of codified guidelines regarding the diagnostic criteria and the eosinophil threshold values for each colonic segment are the main diagnostic challenge for eosinophilic colitis. In addition, eosinophilic colitis is a diagnosis of exclusion, once all other causes of colonic eosinophilia (food allergens, infections, drugs, etc.) have been excluded. Several treatment options are available for eosinophilic colitis, although the evidence for most of them is limited to case reports and small case series. We examine the epidemiology, etiology, pathophysiology, diagnostic criteria and therapeutic options of eosinophilic colitis reporting recent evidence from the current literature.