Disease associations in eosinophilic oesophagitis and oesophageal eosinophilia

Eosinophilic infiltration into oesophageal tissue, typical of eosinophilic oesophagitis (EoE), has been described in several other conditions, including infections, hypersensitivity, and other autoimmune disorders. Since its description, EoE has been associated with an increasing number of diseases also characterized by tissue infiltration, including eosinophilic gastroenteritis and Crohn's disease. While an association between EoE and coeliac disease was previously reported, it is not supported by recent research. In contrast, EoE seems to be common in patients with a history of congenital oesophageal atresia, leading to hypotheses linking both disorders. The prevalence of EoE has also been shown to be eight times higher in patients with connective tissue disorders (CTDs), which has led to the proposal of an EoE-CTD phenotype, although this requires further assessment. This paper reviews the evidence of EoE's associations with several disorders, defining the common bases from an epidemiological, clinical, molecular and genetic perspective whenever possible.