Eosinophilic esophagitis. The North against the South? A bio-economic-social mechanistic approach and clinical implications.

Eosinophilic esophagitis is a chronic antigen-mediated disease characterized by esophageal symptoms, esophageal eosinophilia, and the absence of response to proton pump inhibitors. It is the most frequent cause of dysphagia and food impaction in adults. Its incidence and prevalence is very high in the developed countries (USA, Europe, Australia), where its connotation is that of an emerging epidemic. While studies have been published with large case series in the developed countries, those published in Latin America are small or consist of isolated case reports. The differences in the prevalence of the disease between the developed and developing regions are unknown. Genetic or racial causes have been cited. Nevertheless, the epidemic nature of the disease suggests that environmental causes are the most powerful. Based on the published hypotheses, as well as on epidemiologic studies, the present review discusses some of the possible causes of the disparity in the prevalence of eosinophilic esophagitis between the two types of countries. The 'hygiene hypothesis' is reviewed, together with the possible relation of Helicobacter pylori, intestinal parasites, and modifications of the esophageal microbiota in patients with eosinophilic esophagitis. In reference to studies conducted in the United States, the clinical behavior and progression of eosinophilic esophagitis in Hispanics is reviewed and a possible predominant phenotype in Mexican and other Latin American patients is discussed. Finally, based on the above, an algorithm for studying the disease in the Latin American countries is proposed.