ABSTRACTS: Satellite Symposia Abstracts
NON-IgE MEDIATED FOOD ALLERGY
Satellite Symposium organized by SHS
Food allergies affect about 6% of children in the first 2 years of life. About 40% of these children have non-IgE-mediated reactions and most of these involve the gastrointestinal [GI] tract. While these disorders have been fairly well characterized, the immunopathologic mechanisms responsible for these disorders have not been established. Unlike the IgE-mediated disorders, there are no standard laboratory studies that enable the physician to determine which foods may be accounting for the allergic disorders. Evaluation typically consists of a detailed medical history, non-specific laboratory studies, e.g. CBC with differential, and in many cases, endoscopy and biopsy. Recent studies suggest that patch testing with food allergens may be useful in identifying foods that are responsible for non-IgE-mediated reactions.
Food Protein-induced Enterocolitis Syndrome is most commonly seen in infants prior to 3 months of age, but may be delayed in breast-fed babies. Symptoms are most commonly provoked by cow’s milk or soy protein-based formulas, but may be due to other foods in older children, e.g. various cereal grains, especially rice and oat.
A number of food-induced gastrointestinal hypersensitivities share the feature of marked eosinophil infiltration of the GI mucosa. Food Protein-induced Proctocolitis generally presents in the first few months of life due to food proteins passed in maternal breast milk, or to milk- or soy-based formulas. Lesions are confined to the distal large bowel. Allergic Eosinophilic Esophagitis [AEE] is seen most frequently during infancy through adolescence, and typically presents with chronic gastroesophageal reflux. Allergic Eosinophilic Gastroenteritis [AEG] may occur at any age, including young infants where it may present as pyloric stenosis with outlet obstruction and post-prandial, projectile emesis. Weight loss or failure to thrive is a hallmark of this disorder. AEE and AEG are frequently due to multiple food allergies. While it appears that many children “outgrow” these disorders, the natural history of AEE and AEG are not well established.
Dietary Protein-induced Enteropathy [excluding celiac disease] generally presents in the first several months of life with diarrhea and poor weight gain. Biopsy reveals a patchy villous atrophy, a prominent mononuclear round cell infiltrate and few eosinophils. Most children “outgrow” this disorder in the first few years of life. Celiac Disease [CD] typically presents slightly later and is a more extensive enteropathy leading to malabsorption, and is associated with sensitivity to gliadin found in wheat, rye and barley. IgA anti-tissue transglutaminase and anti-gliadin antibodies are highly diagnostic for this disorder. CD is a life-long disorder.
Infantile Colic is an ill-defined syndrome of paroxysmal fussiness characterized by inconsolable “agonized” crying that generally develops in the first 2 to 4 weeks of life and persists through the third to fourth month of life. Diagnosis can be established by the implementation of several brief trials of hypoallergenic formula.