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Prevalence in adults is estimated at 1/2,370 and in children 1/2,900 in Europe and North America; however, a steady rise in incidence and prevalence is observed. Males are predominantly affected (male/female ratio being 2.5).

Most cases of eosinophilic esophagitis (EoE) present in children and young adults, but it may occur at any age. Infants and toddlers manifest with food refusal, vomiting, choking with meals and in rare cases, failure to thrive. School-aged children most commonly present with dysphagia, choking/gagging with meals, food impactions and, less commonly, regurgitation, vomiting, and chest/abdominal pain. Adults manifest mainly with dysphagia as well as food avoidance, food impactions and intractable heartburn. Symptoms may be chronic or intermittent, with some patients appearing asymptomatic during long periods, although this is mostly due to adaptive behaviors. Overall, symptoms may persist up to 4 to 5 years before a diagnosis is reached. In 75% of cases, there is a personal or family history of other atopic diseases (i.e. dermatitis, rhinitis, asthma). Common food triggers include cow's milk, wheat, egg and, in Mediterranean countries, legumes.

EoE is due to development of a deficient esophageal mucosal barrier and an abnormal immune reaction to environmental allergens mediated by Th2 interleukins causing esophageal lesions, dysmotility, secondary remodeling and fibrosis. The disease is multifactorial with genetic inheritance suggested to contribute a 7% risk of developing the disease; the environment appears to be the main determinant, in particular early-life exposures (including antibiotic use, acid suppression, maternal fever, cesarean delivery, and newborn intensive care unit admission) are associated with increased risk of EoE.

Diagnosis is based on clinical and endoscopic examination of the esophagus revealing linear furrowing, white speckled exudates, concentric rings, Schatzki ring and linear mucosal tears after introduction of endoscope (but in up to 30% of cases the esophagus may appear normal). An esophageal mucosal biopsy is essential in the diagnosis and is based on the presence of at least 15 eosinophils/high power field (HPF), irrespective of the results of pH-monitoring.

Differential diagnoses include gastroesophageal reflux disease, esophageal candidiasis and other local and systemic causes of esophageal eosinophilia (including eosinophilic gastroenteritis and hypereosinophilic syndrome, Crohn's disease involving the esophagus, parasite infectations, drug hypersensitivity, achalasia, vasculitis, phenphigoid, connective tissue disorders and graft-versus-host disease).

PPIs, dietary modifications, or swallowed topical steroids might be offered as first line anti-inflammatory therapy. An effective anti-inflammatory therapy should be used as maintenance treatment in the long term. Endoscopic follow up of any therapy should be 6 to 12-week's after the initial course. Elemental diets are the most effective dietary therapy, but are expensive, badly tolerated and impractical in the long term. Currently, available food allergy tests are suboptimal to predict food triggers, and are typically not recommended. Empiric elimination of most common food triggers is the standard dietary approach. Sequential food reintroduction followed by endoscopies and biopsies identifies specific food triggers. Simpler four-food elimination diet, and specially two-food elimination diet allows faster identification of triggers, with fewer endoscopies. Endoscopic dilation should be considered for fibrostenotic abnormalities, preferably after a trial of anti-inflammatory therapy. Leukotriene receptor antagonist, histamine-1 blockers and mast cell stabilizers are not recommended.

Left untreated, persistence inflammation may lead to fibrosis with stricture formation and functional damage. The disease causes significant emotional distress and restriction of social activities. Both drugs (PPS and steroids) and dietary modification are able to achieve histologic remission, symptomatic improvement and, to some degree, restore quality of life.