Gastrointestinal Manifestations of Food Allergy

Shereen M. Reda


Pediatr Health. 2009;3(3):217-229. 

In This Article

IgE-mediated Gastrointestinal Disorders

Two disorders have been observed in infants and young children. The characteristics of IgE-mediated reactions are summarized in Box 2.

Immediate Gastrointestinal Hypersensitivity 'Gastrointestinal Anaphylaxis'

Gastrointestinal anaphylaxis affects both infants and children.[2] It is characterized by acute onset of nausea and colicky abdominal pains within a few minutes of, and up to 2 h, after food ingestion. Diarrhea may follow several hours after the initial symptoms. GI symptoms may occur in association with other target-organ responses (urticaria and bronchial asthma), as well as during systemic anaphylaxis in atopic patients. Skin-prick tests (SPTs) and in vitro serum-specific IgE to the causal protein are usually positive. The classic offenders are milk, egg, wheat, soy, peanut and seafood.[7]

Oral Allergy Syndrome: 'Pollen Food Allergy'

Oral allergy syndrome (OAS) usually occurs in late childhood.[2] The reported peak incidence is at 11-15 years of age and occurs rarely in those younger than 8 years. It is more common in patients with seasonal allergic rhinitis.[8,9,10] Allergic symptoms are exclusively confined to the oropharynx, and include swelling of the lips, tongue and throat (angioedema) (Figure 1). However, approximately 9% of individuals experience symptoms beyond the mouth and 1-2% of patients show severe reactions up to anaphylaxis.[7] Symptoms develop within a few minutes after the ingestion of raw fruits and vegetables, but when these allergenic foods are cooked they do not produce the reaction.[9,10] The reaction is caused by heat-labile food proteins (plant proteins) that show crossreactivity with allergenic pollen proteins (aeroallergens).[8] These allergic symptoms are commonly seen in patients sensitized to birch-tree pollen after the ingestion of raw apples, pears, cherries, carrots, potatoes, celery, hazelnuts and kiwis. In addition, patients allergic to ragweed react to fresh melons and banana. Other fruits, vegetables and nuts that have been reported to cause OAS include kiwis, peaches, apricots, plums and cherries, which cross-react with chestnuts, spinach and grapes.[7,10] The diagnosis of OAS is confirmed by clinical history and positive SPT with a fresh food extract of the culprit food. Oral challenge test is usually positive when the raw food is tested and negative when the same food is cooked.[11]

Figure 1.

Occurrence of rapid swelling of lips and periorbital edema (angioedema) shortly after the intake of a specific food denotes IgE-mediated reaction.

Mixed IgE- & Cell-mediated Disorders: 'Allergic Eosinophilic Gastroenteropathies'

This group of heterogeneous disorders is characterized by eosinophilic infiltration of the gut. According to the anatomical site of eosinophilic infiltration, two main disorders are recognized, eosinophilic esophagitis (EE) and eosinophilic gastroenteritis (EG).[2,5] In general, symptoms of these disorders overlap those of other GI diseases. The diagnosis requires confirmation of an eosinophilic infiltration of the gut by biopsy and the exclusion of other causes of eosinophilia such as parasitic infestation, inflammatory bowel disease and vasculitis.[12]

Eosinophilic esophagitis has been reported in all age groups, including infants, and there is a predominance of boys over girls. Symptoms overlap with those of gastroesophageal reflux disease (GERD) such as nausea, dysphagia, vomiting and epigastric pain. EE should be suspected in any patient with dysphagia or with food impaction in the esophagus, and when there is failure to respond to conventional reflux medications.[13,14,15] Meanwhile, EG is marked by eosinophilic inflammation in the bowel distal to the esophagus and can involve the entire remainder of the GI tract.[16,17] The clinical presentation is often nonspecific, including vomiting, diarrhea, abdominal pain and poor weight gain.[12] Atypical presentations of EG include subacute bowel obstruction,[18] neonatal intussusception,[19] gastric outlet obstruction, duodenal strictures and acute appendicitis.[20]

Pediatric patients with eosinophilic GI diseases have evidence of food allergy, especially to cow's milk and egg. This was supported by the resolution of symptoms with the use of elimination diet in several cases.[13,14,15,21,22] The role of aeroallergens sensitivity, especially in EE, was also highlighted since 50-80% of patients have coexistent asthma, allergic rhinitis and/or atopic dermatitis.[21,22]


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.