DISCUSSIONS IN MEDICINE: ALLERGY OR FOOD INTOLERANCE

Abstract

Clinicians and patients often confuse hypersensitivity, allergies and intolerances. Differences in terminology often lead to erroneous conclusions. This article proposes the terminology to split up symptoms that are very close to each other clinically, however are totally different in pathways.

Objective: to describe differences between the discussed terms for practitioners from the position of a pediatric gastroenterologist.

Results: many patients present with symptoms «related to food ingestion». We propose to use exactly that wording if it is impossible to establish specific pathogenic mechanisms underlying the clinical manifestations. We propose to understand the term intolerance as the clinical manifestations that occur in patients on the background of malabsorption of carbohydrates. Allergy refers to the involvement in the pathological process of IgE - and not IgE-mediated reactions resulting in clinical manifestations such as atopic dermatitis or allergic colitis with the appearance of blood in the stool. Unfortunately, primary care physicians don’t have possibilities to diagnose non-IgE-mediated allergies. A positive provocative test proves the presence of symptoms induced by food, but does not prove involvement in the pathological process of the immune system. The term «hypersensitivity» involves immunological mechanisms and should not be used in this case. The pathophysiologic mechanism of many symptoms that occur when eating remains unclear. The same symptom can be caused by allergies or it can be a manifestation of functional disorders of the gastrointestinal tract, such as infant intestinal colic, gastroesophageal reflux and constipation that occurs on the background of infant feeding products based on cow’s milk. In practice, the term functional is used in that case, if the pathophysiological mechanism inducing the symptom can be explained. The distant outcome of allergies is significantly different from the outcome of functional disorders, therefore, correct differential diagnosis of these states is essential.

Conclusion: the phrase «a symptom that occurs when eating food,» should be used if its pathophysiological mechanism is not clear. Food intolerance should identify symptoms due to malabsorption of carbohydrates. The term allergy should be used in those cases when the pathological process is involved the immune system.