Allergic Eosinophilic Esophagitis

EE was first described by Attwood et al as a distinct clinical entity in 1993. He reported a series of 12 patients with isolated oesophageal eosinophilia and reflux (1).

Clinical Features include:

  • The patients presented with dysphagia and had visually normal oesophageal mucosa, >20 oesophinils per HPF on biopsy (mean 56 eosinophils /HPF
  • Normal 24 hour pH probe monitoring (no reflux) in 11 patients
  • Allergic diseases in 7 patients

In 1995 Hugh Sampson et al described a series of 10 children with abdominal pain after eating, early satiety or food refusal, vomiting or retching, failure to thrive, and non-responsiveness to standard medical therapy (2).

All these patients were treated for several years with various antacids and H2-antihistamines (Ranitidine and Cimetidine), prokinetic agents (omeprazole), and oral steroids. 4 out of the 10 even had a surgical procedure (Nissan fundoplication) for their persistent “reflux” and vomiting.

On endoscopy these patients had normal looking oesophageal mucosa, but marked eosinophilia on microscopy.

Following 6-8 weeks of an amino acid-based formula (Neocate) plus rice, symptoms completely resolved in 8 patients and markedly improved in the other 2.

Improvement (decreased eosinophilia) was also seen on repeat biopsy.

Symptoms could be reproduced with the introduction of certain foods. This study clearly implicated food hypersensitivity in patients with allergic eosinophilic espohagitis.

Foods responsible for vast majority of symptoms include:

  • Milk
  • Egg
  • Soy
  • Wheat and other cereal grains
  • Beef
  • Chicken

It is now well recognized, as an increasingly common disease found in all ages, but more common in children. The hallmark of the disease is intermittent and often painful difficulty swallowing (dysphagia). It is often misdiagnosed as Gastro-eosophageal reflux disease (GERD), but if these patients are investigated properly, they will be found to have normal or only mildly abnormal oesophagus on gross inspection at endoscopy. The pH and manometry studies are inconsistent with the severity of symptoms. No mechanical obstruction is found, and if a biopsy is not taken the diagnosis is often missed.

In a subset of patients with EE, food-induced IgE-mediated reactions have been implicated in the pathogenesis.

Associated features:

  • EE is commonly associated with asthma in 70% of cases
  • 70% also have positive skin prick tests and
  • 50% have peripheral eosinophilia

Aetiology is unknown, but food allergen or swallowed or inhaled airborne allergen is suspected as a probable link.

Common presenting symptoms include:

  • Vomiting
  • Painful dysphagia (difficulty swallowing)

Investigations

  • 24 hour pH probe is normal vs GERD
  • Endoscopy shows the following pathologic changes in the upper & mid-oesophagus:
  •                 - Charactersitic punctate white surface dots with erythema                 - Ulcers                 - Ringed, trachea-like appearance
  • Histology: Large numbers of intraepithelial eosinophils (>20/ high power field). These are usually found in the upper half of the epithelium

Treatment

  • Anti-inflammatory agents in oral form like prednisone or topically in the form of Flixotide
  • If food allergens are identified by skin prick test, RAST or Patch Test, an exclusion diet should be tried for 6 weeks.
  • Montelukast is a Leukotrienereceptor antagonist, which was originally licensed for the treatment of asthma. A recent report by Schwartz and colleagues described the successful use of Montelukast in steroid dependent patients with EE.

Conditions that are confused with EE include:

  • GERD
  • Infection
  • Radiotherapy damage

Comparison of Allergic Eosinophilic Esophagitis (AEE) with Reflux (GER)

  • Symptoms of epigastric pain, dysphagia and vomiting are common to both
  • Reflux occurs as a secondary occurrence in some patients with AEE, but in all patients with GER, hence pH probe is usually normal in AEE
  • Barium swallow may show reflux in both
  • Histology usually shows >15 eosinophils/HPF in AEE, but 0-3 eos/HPF in GER
  • Peripheral (Blood) eosinophilia is seen in 50% of patients with AEE, but rare in GER
  • Atopy is present in about 50% of patients with AEE, but non-specific in GER

References
(1)Attwood SEA, Smyrk TC et al. Esophageal oesinophilia with dysphagia. A distinct clinicopathologic syndrome. Dig Dis Sci 1993; 38:109-16

(2)Kelly KJ, Sampson HA et al. Eosinophilic esophagitis attributed to gastrooesophageal reflux: improvement with an amino-acid based formula. Gastroenterol 1995; 109(5):1503-12

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