Eosinophilic colitis

Abstract

Eosinophilic colitis (EC) is a rare form of primary eosinophilic gastrointestinal disease with a bimodal peak of prevalence in neonates and young adults. EC remains a little understood condition in contrast to the increasingly recognized eosinophilic esophagitis. Clinical presentation of EC is highly variable according to mucosal, transmural, or serosal predominance of inflammation. EC has a broad differential diagnosis because colon tissue eosinophilia often occurs in parasitic infection, drug-induced allergic reactions, inflammatory bowel disease, and various connective tissue disorders, which require thorough searching for secondary causes that may be specifically treated with antibiotics or dietary and drug elimination. Like eosinophilic gastrointestinal disease involving other segments of the gastrointestinal tract, EC responds very well to steroids that may be spared by using antihistamines, leukotriene inhibitors and biologics.

Figure 1

Diagnostic findings in EC. Representative images from a case of a previously healthy 30-year-old man with recurring episodes of abdominal pain, non-bloody diarrhea, and peripheral eosinophilia; extensive workup confirming EC by exclusion; and excellent response to short-term steroid therapy. A and B: Abdominal CT shows circumferential colon wall thickening (arrows) and moderate ascites (asterisks); C-E: Colonoscopy reveals patchy areas in the colon with mucosal edema and punctate erythema; F and G: Histology indicates markedly increased tissue eosinophilia in all examined segments of the colon. HE stains, magnification 100 × and 400 ×, respectively.