It is seen mainly in children and young adults; patients have dysphagia or food impaction in the emergency room.
Eosinophilic esophagitis or EoE (also known as “esophageal asthma”) is a chronic antigenic immune disorder of the esophagus that affects children and adults. It is a clinicopathological disease characterized clinically by dysphagia and pathologically by esophageal eosinophilia.
There has been an epidemic of this condition in the Western world in the last decade.
The characteristic endoscopic findings, esophageal eosinophilia, and lack of response to proton pump inhibitors help make the diagnosis.
Avoiding food allergens, administering steroidal anti-inflammatory drugs, and dilating the esophagus are the pillars of treatment.
Research is underway for mucosal healing and optimal maintenance treatment.
The diagnosis is made using three criteria:
- Symptoms of esophageal dysfunction.
- Presence of eosinophils in the high power field in at least one esophageal biopsy with few exceptions.
- Eosinophilia is limited to the esophagus, excluding other possible causes of esophageal eosinophilia, including proton pump inhibitors (PPIs) that respond to esophageal eosinophilia.
Epidemiology of Eosinophilic Esophagitis
The disease is more common in the Caucasian population, with more proportion in men than in women. Eosinophilic esophagitis has also been seen in African-Americans, Asians, and Hispanics.
The disease has been increasingly recognized in recent decades. The prevalence of EoE is currently as high as 50 patients per 100,000 population in the United States and Europe.
The disease can affect both children and adults. It mainly affects middle-aged men between 30 and 50 years old in adults.
Most patients with eosinophilic esophagitis have a personal history of allergic disorders such as bronchial asthma, allergic rhinitis, allergic conjunctivitis, or food allergy.
Exposure of the esophagus to food and aeroallergens in genetically predisposed individuals may initiate the process of eosinophilic esophagitis, although the exact mechanism is currently unknown.
The foods most commonly involved in EoE are milk, egg, wheat, soy, peanuts, beans, rye, and meat.
The genome-wide association analysis (GWAS) suggested that CAPN14 at the 2p23 locus is promulgated after epithelial exposure to interleukin.
Recently, the thymic cytokine stromal lymphopoietin (TSLP) gene derived from the epithelium at the 5q22 locus has been identified as a candidate gene in a multicentric GWAS.
There is an increased expression of TSLP in patients with EoE. TSLP activates dendritic cells (antigen-presenting cells).
The main characteristics include the infiltration of numerous eosinophils, generally by high power field) in the squamous epithelium, stratification of eosinophils in the superficial layer and formation of eosinophilic microabscesses groups of 4 eosinophils
Often, necrotic squamous cells are also seen in the superficial layer.
Minor characteristics include chronic inflammatory infiltrate in the lamina propria with fibrosis of the lamina propria, hyperplasia of the muscular layers, and basal epithelial cells with lengthening of the lamina propria of the papillae and intercellular edema.
One study showed many plasma cells containing IgG4 in the lamina propria. The pathological changes are unequal in the distribution and generally affect the entire length of the esophagus.
None of the histological findings is specific to eosinophilic esophagitis. Esophageal eosinophilia can be found in various disorders, including gastroesophageal reflux disease (GERD).
Oesophageal eosinophilia is receptive to the proton pump (PPI-REE), eosinophilic gastroenteritis, hypereosinophilic syndrome, Crohn’s disease, connective tissue diseases, hypersensitivity to medications, parasitic and fungal infections, and achalasia.
The real challenge is differentiating EoE from GERD and PPI-REE in clinical practice. Eosinophilic degranulation is seen more deeply in EoE than in the GERD biopsy sample. EoE, eosinophilic inflammation extends beyond the mucosa to the submucosa and the muscularis propria.
Symptoms of Eosinophilic Esophagitis
The main symptoms of eosinophilic esophagitis are solid alimentary dysphagia and the esophageal alimentary impaction that requires the endoscopic elimination of the alimentary bolus in an emergency case.
In one study, EoE was found in 9% of all cases of esophageal alimentary impaction.
Commonly, diagnosis is suspected after the first episode of esophageal food impaction and biopsy showing esophageal eosinophilia.
Less frequently, patients have heartburn and chest pain that mimic gastroesophageal reflux disease.
One study found that gender was an essential factor in the initial clinical presentation of eosinophilic esophagitis. Men presented dysphagia and esophageal alimentary impaction more commonly than women.
Women presented heartburn and chest pain more frequently than men.
Diffuse narrowing of the esophageal lumen has been seen in clinical practice due to chronic inflammation and fibrosis.
The esophageal mucosa is friable and esophageal perforation has been reported during the endoscopic removal of the esophageal foreign body and dilation of esophageal stenosis.
As aeroallergens play an essential role in pathogenesis, eosinophilic esophagitis was diagnosed more frequently when the environmental pollen count (grass, trees, and weeds) is high; the highest percentage of EoE occurred in the spring and the lowest rate in the winter.
Another study showed that symptomatic esophageal eosinophilia was diagnosed more frequently in the December / January and May / June periods.
Although eosinophilic esophagitis is an important differential diagnosis in dysphagia and acute impaction with food bolus, the understanding and treatment of this disease are still in their infancy. It is now considered the second most common cause of chronic esophagitis.