Outlines on Diseases related to a Food Allergy
Food allergies, occurring because proteins, that are present in foods we eat, are erroneously recognised as “dangerous” by our immune system, which normally protects us from infectious agents, often develop in genetically predisposed individuals, probably when oral tolerance fails to develop normally. But not all food allergies show the same symptoms and mechanism of response.
Indeed, allergic reactions to foods can be characterized both by an overproduction of antibodies and by a hyper activation of other cells. Thus, these different food allergies derive from different diseases, can show various symptoms and can show up after a variable amount of time from food injestion (latency time). Here is a summary of the differences:
1. FOOD ALLERGIES CHARACTERIZED BY AN OVERPRODUCTION OF ANTIBODIES (the so-called IgE - mediated food allergies) Latency time: - Immediate, acute onset (whithin 2-3 hours)
Main related diseases: |
2. FOOD ALLERGIES CHARACTERIZED BY BOTH AN OVERPRODUCTION OF ANTIBODIES AND A HYPERACTIVATION OF OTHER CELLS (the so called mixed IgE- and cell- mediated food allergies) Latency time: - Medium onset reactions (from 2 to 24 hours after food injestion)
Main related diseases: Endoscopy and biopsy are necessary for the most definitive diagnostic approach for many gastrointestinal hypersensitivities. |
3. FOOD ALLERGIES CHARACTERIZED BY A HYPERACTIVATION OF OTHER CELLS (the so called cell mediated food allergies) Latency time: - Late onset reactions (24 hours after food injestion onwards)
Main related diseases: - Gastrointestinal: Food protein-induced enterocolitis, food protein-induced proctocolitis, food protein-induced enteropathy syndromes, coeliac disease
- Cutaneous: Contact dermatitis, dermatitis herpetiformis
- Respiratory: Food-induced pulmonary hemosiderosis (Heiner syndrome)
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Currently, the two main tests useful to help in the identification of a food allergy as the cause of dermatitis in babies are the skin prick test and the atopy patch test.
by Professor Christophe Dupont
Date of publication: 20/05/2010