lesson 16

lesson 16 - What is a food allergy? A food allergy is an...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
What is a food allergy? A food allergy is an immune system response to a food that the body mistakenly believes is harmful. Although an individual could be allergic to most any food, there are eight foods that account for 90% of all food-allergic reactions. These are: milk, egg, peanut, tree nut (walnut, cashews, almonds, and so forth), fish, shellfish, soy and wheat. Once the immune system decides that a particular food is harmful, it creates specific antibodies to it . This involvement of the immune system is what sets a true food allergy apart from other adverse food reactions. The antibodies produced by the immune system begin a chain of reactions leading to the manifestation of allergic symptoms that can affect the respiratory system, gastrointestinal tract, skin, or cardiovascular system. Scientists estimate that approximately 12 million Americans suffer from true food allergies. A true food allergy is an immediate, consistent, immune-mediated reaction to a food that is largely dose-dependent and usually begins in childhood . Another hallmark of a food allergy is that the reaction is not seen until the second (or later) exposure to the food product, giving the body the chance to produce the necessary antibodies. Adverse reactions to food- An adverse reaction to a food is any unexpected reaction to a food whether mediated by the immune system or not. The perceived prevalence is 6-8% in children, and 1-2% in adults. Many people with confuse food intolerance with food allergies. Food intolerances are adverse reactions to food that do not involve the immune system. Lactose intolerance is one example of a food intolerance. The immune response to an allergen (take notes on the animation too) A food allergy occurs when the immune system reacts to a protein by producing immunoglobulin E (IgE) antibodies to a protein. These IgE antibodies cover the surfaces of mast cells which line the respiratory tract, gastrointestinal tract, and are found in the skin. When eaten or inhaled, the allergen will react with the IgE antibodies on the mast cells, releasing histamine and causing swelling and itching of the skin and throat, sometimes diarrhea and vomiting and, if left untreated, may cause anaphylaxis and death. Case Studies: An 11 year old girl suffers from recurrent headaches and behavioral problems. Her mother has noted that her symptoms worsen whenever she eats chocolate, strawberries, cocoa-cocoa puffs, or drinks soda. A mother says her 5-year old son ‘goes crazy’ when he eats popsicles or drinks any beverage with
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 10/08/2008.

Page1 / 6

lesson 16 - What is a food allergy? A food allergy is an...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online