Adverse Reactions of Food in Pediatrics

Abstract

An adverse food reaction consists of any abnormal reactions to the ingestion of food or food additives. They are classified into toxic and non-toxic reactions. Toxic reactions occur to anyone who expose to the contaminated food e.g. toxic food poisoning, toxicity with heavy metals. Non-toxic reactions could be classified into immune mediated (food allergy) and non-immune mediated (food intolerance). It depends on host factors, genetic factors and environmental factors. Food allergy can be classified into IgE mediated, cell mediated and mixed IgE and cell mediated reactions. It is more common in infants and children and it decreases by age. It is the most common cause of anaphylaxis in the USA. It could be represented by anaphylaxis, skin symptoms (urticaria, itching, flushing, eczema), gastrointestinal symptoms (symptoms extending from the oral cavity to the anus), respiratory symptoms (sneezing, rhinorhea, cough, dyspnea), cardiovascular symptoms (hypotension, arrhythmia). It leads to nearly 30000 cases of anaphylaxis to the emergency department, 2000 cases of hospital admission and 200 deaths annually in the USA. Although any food can trigger an allergic response and there are more than 170 foods reported to cause food allergy, the major food allergens are peanut, tree nuts, egg, milk, fish, crustacean shellfish, wheat and soy. Food allergy can be diagnosed by detailed history, physical examination, some investigations (sIgE, skin prick test, oral food challenge test) and in some cases endoscopy. The main line of treatment of food allergy is avoidance of the causative food. Immunotherapy is still under trials. Food intolerance is a physiologic reaction. It may be due to enzyme deficiency, malabsorption and usually it is dose dependent. It is believed that it represents the majority of adverse food reactions. Food intolerance symptoms may involve the gastrointestinal tract (gastric pain, distention), the nervous system (headache), skin (skin rash) and respiratory system (rhinorrhea, cough). It can be diagnosed by history, diet elimination and some investigation. It is treated by avoidance of the causative food and enzyme supplementation in some cases of enzyme deficiency.