Table 2.

Underlying diseases associated with gastrointestinal (GI) mucosal eosinophilia.

Underlying disease	Affected GI site
Food allergy	Any site
Gastroesophageal reflux disease	Esophagus
Inflammatory bowel disease	Small intestine, colon
Parasitic infections	Any site, e.g., stomach, small intestine (Anasakis, Helicobacter pylori), proximal small intestine (Strongyloides stercoralis, Giardia), small intestine, colon (Cryptosporidium), small intestine (Ascaris lumbricoides), colon (Entamoeba histolytica, Dientamoeba fragilis, Blastocystis species, Balantidium coli, Trichuris trichiura), distal small intestine (Angiostrongylus costaricensis), proximal colon, and appendix (Enterobius vermicularis)
Drug reactions	Any site including medication-induced (“pill-induced”) esophagitis
Systemic mastocytosis	Small and large intestine
Neoplasm, e.g., leiomyomatosis, granular cell tumor	Esophagus
Vasculitis e. g., eosinophilic granulomatosis with vasculitis (Churg-Strauss syndrome), granulomatosis with polyangiitis, microscopic polyangiitis	Any site
Connective tissue disease (e. g., systemic sclerosis)	Any site
Hypereosinophilic syndrome	Any site
Celiac disease	Esophagus, duodenum
Organ transplant	Any site