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Food allergies and food intolerances ppt

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Food allergies and food intolerances ppt

  1. 1. Food Allergies and Food Intolerances Presented by Dev ram Sunuwar M.Sc. Nutrition and Dietetics 12/2/20171-31 1
  2. 2. By the end of presentation, participants will be able to:- Define a food allergy and food intolerance Describe the types of food allergy and food intolerance How do allergic reaction work List the sign and symptoms of food allergy Identify the “Big 8” food allergen Describe the diagnosis and management of food allergy and food intolerance OBJECTIVE 12/2/20171-31 2
  3. 3. An Overview of Food Allergies Definition Type of food allergy and food intolerance Mechanism of action Sign and symptoms Most common food allergens Diagnosis Management Conclusion SCOPE 12/2/20171-31 3
  4. 4.  As many as 15 million people have food allergies.  An estimated 9 million, or 4%, of adults have food allergies.  Nearly 6 million or 8% of children have food allergies with young children affected most. In 2008, the CDC reported an 18 percent increase in food allergy among children between 1997 and 2007 (CDC) According to a study released in 2013 by the Canters for Disease Control and Prevention, food allergies among children increased approximately 50% between 1997 and 2011. (Food Allergy Research & Education) 12/2/20171-37 4 Overview
  5. 5. 5 What is food allergy? Food allergy is an abnormal response to a food triggered by the body’s immune system. Allergic reactions to food can cause serious illness or even death. What is food intolerance ? An abnormal physiological response to eating Food intolerance is caused by the lack of our body’s ability to digest certain substances. Some people may have a food intolerance that has a psychological trigger. Food allergy is different with food intolerance although both can show similar symptoms. 12/2/20171-31
  6. 6. Types of food allergies 12/2/20171-31 6 Source: Adapted from Boyce et al. JACI, 2010
  7. 7. IgE mediated food allergy Reactions occur when allergens bind to Immunoglobulin E (IgE) antibodies bound to mast cells, resulting in the release of histamine and other inflammatory mediators.  Symptoms are usually of rapid onset (<30 minutes in children, usually <2 hours in adults).  Diagnostic tests (e.g. skin prick and blood tests) are usually positive. 12/2/20171-31 7
  8. 8. Non IgE mediated food allergy.  Reactions occur when the ingested food protein causes an immune response resulting in delayed  normally in the skin or gastrointestinal tract.  Symptoms usually occur 2-24 hours after ingestion of the food protein.  Diagnostic tests are usually negative. There is no definitive in vitro test for non IgE mediated food allergies.  Mixed IgE and non IgE symptom clusters (of the above) can occur. Non IgE mediated can convert to IgE mediated allergy and therefore long term follow up is essential 12/2/20171-31 8
  9. 9. Food Intolerance Food poisoning: Histamine toxicity Lactose intolerance Food additives, such as:  MSG  Sulfites 12/2/20171-31 9
  10. 10. How do allergic reactions work? An immediate allergic reaction involves two actions of our immune system: Our immune system produces immunoglobulin E (IgE) – a type of protein that works against a specific food – antibody. IgE attaches basophils (white blood cells) and to mast cells – cells found in all body tissues. The typical sites of allergic reactions include nose, throat, lungs, skin and GI tract. 12/2/20171-31 10
  11. 11. How do allergic reactions work? Food allergens are proteins within the food that enter our bloodstream after the food is digested. Food allergen go to target organs such as skin, nose, etc and cause allergic reactions. An allergic reaction to food can take place within few minutes to an hour. 12/2/20171-31 11
  12. 12. 12/2/20171-31 12
  13. 13. How do allergic reactions work? The symptoms of cell-mediated allergic reactions do not begin to appear until 6–24 hrs after ingestion of the offending food. These reactions develop slowly, reaching a peak at approx. 48 hrs and subsiding after 72– 96 hrs. The mechanisms of cell-mediated food allergies are not nearly as well understood. They involve an interaction between specific food allergens and sensitized T lymphocytes - a major component of the gut-associated lymphoid tissue. Lymphocyte stimulation initiates the release of cytokines and lymphokines which produces a localized inflammatory response. Antibodies are not involved in these reactions. 12/2/20171-31 13
  14. 14. 14 Examples of Allergic Conditions and Symptoms Skin and Mucous Membranes  Atopic dermatitis (eczema)  Urticaria (hives)  Angioedema (swelling of tissues, especially mouth and face)  Pruritus (itching)  Contact dermatitis (rash in contact with allergen)  Oral symptoms (irritation and swelling of tissues around and inside the mouth)  Oral allergy syndrome 12/2/20171-31
  15. 15. 15 Examples of Allergic Conditions and Symptoms Digestive Tract  Diarrhea  Constipation  Nausea and Vomiting  Abdominal bloating and distension  Abdominal pain  Indigestion (heartburn)  Belching 12/2/20171-31
  16. 16. 16 Examples of Allergic Conditions and Symptoms Respiratory Tract  Seasonal or perennial rhinitis (hayfever)  Rhinorrhea (runny nose)  Allergic conjunctivitis (itchy, watery, reddened eyes)  Serous otitis media (earache with effusion)  Asthma  Laryngeal oedema (throat tightening due to swelling of tissues) 12/2/20171-31
  17. 17. 17 Examples of Allergic Conditions and Symptoms Nervous System  Migraine  Other headaches  Spots before the eyes  Restlessness  Hyperactivity  Lack of concentration  Tension-fatigue syndrome  Irritability  Chilliness  Dizziness 12/2/20171-31
  18. 18. 18 Anaphylaxis Severe reaction of rapid onset, involving most organ systems, which results in circulatory collapse and drop in blood pressure In the most extreme cases the reaction progresses to anaphylactic shock with cardiovascular collapse This can be fatal 12/2/20171-31
  19. 19. 12/2/20171-31 19 Most Common Food Allergens
  20. 20. Food Allergy Tests  Diagnosis of allergy is based on a combination of: Clinical history.  Skin tests Identifying the type of IgE that is fixed to the skin mast cell. For example: scratch test. Blood tests  analyze CBC, TFT, GRBS and Urine R/E RAST (radioallergosorbent test) or ELISA ( enzyme-linked immunosorbent assay). These tests measure the presence of food-specific IgE in blood and the total IgE level in blood. 12/2/20171-31 20
  21. 21. 12/2/2017 21 Procedure for skin prick test Fig. KU TH
  22. 22. 1-31 Management of food allergy Symptomatic pharmacotherapy Dietary avoidance hyposensitization, anti-IgE antibodies, and DNA vaccination with allergen DNA. Counseling: nutritional, psychological HACCP can be adapted to identify and control potential food allergy problems before they happen. 12/2/201722
  23. 23. 23 Emergency Treatment for Anaphylactic Reaction Transport to hospital immediately Inj adrenaline I/v Fast-acting antihistamine corticosteroid Second phase of reaction is sometimes fatal, especially in an asthmatic Patient may appear to be recovering, but 2-4 hours later symptoms increase in severity and reaction progresses rapidly 12/2/20171-31
  24. 24. Dietary avoidance Avoiding to eat foods which can trigger allergic reaction. Strict avoidance of food allergens and early recognition and management of allergic reactions to food are important measures to prevent serious health consequences.  The allergenic capacity of some food allergens is destroyed by cooking and food processing, when the proteins are denatured. Newer processing techniques, such as high-pressure treatment of foods, fermentation and enzyme treatment, can help to reduce the allergenic and intolerance of some food proteins. Anti-oxidants prevent damage to body tissues caused by free radicals which are very reactive small chemicals entities produced during biochemical reactions in the body tissues. Vitamin C (or ascorbic acid) is a potent anti-oxidant and can also act as natural mild anti-histamine. 12/2/20171-31 24
  25. 25. Consumer Protections & Labeling Food manufacturers are generally responsible about posting alerts concerning allergen contamination and recalling their products. Labeling of foods containing allergens have to be clear and consistent. The application of GMP in food manufacturing to avoid cross-contamination of food products by foreign allergens. The awareness of the consumers in checking the labels. 12/2/20171-31 25
  26. 26. The Codex recommendations  The Codex Alimentarius Commission Committee on Food Labelling has listed the foods and ingredients that cause the most severe reactions and most cases of food hypersensitivity. The following foods and ingredients are known to cause hypersensitivity and shall always be declared:  Cereals containing gluten; i.e., wheat, rye, barley, oats, spelt or their hybridized strains and products of these;  Crustacea and products of these;  Eggs and egg products;  Fish and fish products;  Peanuts, soybeans and products of these;  Milk and milk products (lactose included);  Tree nuts and nut products; and  Sulphite in concentrations of 10 mg/kg or more.” 12/2/20171-31 26
  27. 27. EU and US regulation The European Union (EU) directive (EU Directive 2003/89/EC amending 2013/EC) makes it mandatory for the food industry to list 12 potential food allergens on the product labels regardless of the quantity in the finished product. The United States of America In the United States, the Food Allergen Labelling and Consumer Protection Act 2004 (FALCPA) of the US Food and Drug Administration (USFDA) mandates manufacturer disclosure of the most common allergens (milk, egg, wheat, soy, peanut, tree nuts, fish and crustacean shellfish) in plain English, using the common or usual name, in the ingredient list or in a separate allergens summary statement. 12/2/20171-31 27
  28. 28. It is important to understand there is currently no cure of food allergies staying away from the food that causes food allergies is the best way to avoid the allergies The most common food allergens include peanuts, milk, eggs, tree nuts,fish, shellfish, soy, and wheat — these foods account for about 90% of all allergic reaction Food allergy is treated primarily by dietary avoidance People who have food allergies must identify and prevent them because, although usually mild and not severe, these reactions can cause devastating illness and, in rare instances, can be fatal 12/2/20171-31 28 Conclusion
  29. 29. ASCIA Health Professional Information Paper (2013). Nutritional Management of Food Allergy  U.S. Department of Health and Human Services (2004).Food Allergy: An Overview. Retrieved from Janice M. Joneja, Ph.D.(2013) Food Allergies and Food Intolerances Rai k.p. class notes ppt 12/2/20171-31 29 References
  30. 30. Thank You! 12/2/20171-31 30
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