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Diagnosis and Dietary Management of Food Allergy and Intolerance

Diagnosis and Dietary Management of Food Allergy and Intolerance. Clinical Practice. Major Allergenic Foods : Annex IIIa EU Directive on Labeling of Foods Which Must be Declared. Cereals containing gluten Crustaceans Eggs Fish Peanuts Soybeans Milk (including lactose) Nuts Celery

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Diagnosis and Dietary Management of Food Allergy and Intolerance

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  1. Diagnosis and Dietary Management of Food Allergy and Intolerance Clinical Practice

  2. Major Allergenic Foods:Annex IIIa EU Directive on Labeling of Foods Which Must be Declared • Cereals containing gluten • Crustaceans • Eggs • Fish • Peanuts • Soybeans • Milk (including lactose) • Nuts • Celery • Mustard • Sesame seeds • Sulphur dioxide and sulphites at concentrations of more than 10mg/kg or 10 mg/litre

  3. Priority Food Allergens In Canada • Peanuts • Tree nuts (almonds, Brazil nuts, cashews, hazelnuts (filberts), macadamia nuts, pecans, pinenuts, pistachios, walnuts) • Sesame seeds • Milk • Eggs • Fish • Shellfish (e.g. clams, mussels, oysters, scallops and crustaceans (e.g. crab, crayfish, lobster, shrimp) ) • Soy • Wheat • Sulphites These Priority Allergens account for more than 95% of severe adverse reactions related to food allergens

  4. U.S. Food and Drug AdministrationFood Allergen Labeling and Consumer Protection ActJanuary 2006 • Milk • Egg • Fish (e.g., bass, flounder, or cod) • Crustacean shellfish (e.g., crab, lobster, or shrimp) • Tree nuts (e.g., almonds, pecans, or walnuts) • Wheat • Peanuts • Soybeans “These 8 major allergens account for 90 percent of food allergies“

  5. Additional Factors Involved in Symptoms of Food Sensitivity 1. Increased permeability of the GI tract • Inflammation: • Infection • Allergy • Autoimmune processes • Other pathology • Immaturity (in infants) • Alcohol ingestion 2. Physical exertion

  6. Additional Factors Involved in Symptoms of Food Sensitivity 3. Stress 4. Level of inflammatory mediators released in response to several different foods concomitantly 5. Level of inflammatory mediators released in response to other allergy (e.g. inhalant)

  7. Diagnosis of Food Allergy Detecting the Culprit Foods and Food Components

  8. Tests for Food Allergies:Drawbacks of Unreliable Tests • Diagnostic inaccuracy • Therapeutic failure • False diagnosis of allergy • Creation of fictitious disease entities • Failure to recognize and treat genuine disease • Inappropriate and unbalanced diets • Malnutrition

  9. Consequences of Mismanagement of Adverse Reactions to Foods • Malnutrition; weight loss, due to extensive elimination diets • Especially critical in young children where nutritional deficiency at a crucial stage in development can cause permanent damage • Food phobia due to fear that “the wrong food” will cause permanent damage, and in extreme cases, death • Frustration and anger with the “medical system” that is perceived as failing them • Disruption of lifestyle, social and family relationships

  10. Risks associated with skin tests • High number of false positive and false negative tests • Many allergists claim only 30% accuracy in identification of food components responsible for adverse reactions • Danger of sensitisation to allergens through the skin: • Initial exposure via the digestive tract most likely to lead to tolerance • Initial exposure via the skin more likely to lead to sensitization and initiation of allergy

  11. Elimination and Challenge Protocols

  12. Identification of Allergenic Foods • Removal of the suspect foods from the diet, followed by reintroduction is the only way to: • Identify the culprit food components • Confirm the accuracy of any allergy tests • Long-term adherence to a restricted diet should not be advocated without clear identification of the culprit food components

  13. Increase Restrictions Symptoms Disappear Symptoms Persist Reintroduce Foods Sequentially or Double-blind Symptoms Provoked No Symptoms Diagnosis Not Confirmed Diagnosis Confirmed Food Intolerance: Clinical Diagnosis Elimination Diet: Avoid Suspect Food

  14. Elimination and Challenge Stage 1: Exposure Diary • Record each day, for a minimum of 5-7 days: • All foods, beverages, medications, and supplements ingested • Composition of compound dishes and drinks, including additives in manufactured foods • Approximate quantities of each • The time of consumption

  15. Exposure Diary (continued) • All symptoms graded on severity:  1 (mild);  2 (mild-moderate)  3 (moderate)  4 (severe) • Time of onset • How long they last • Record status on waking in the morning. • Was sleep disturbed during the night, and if so, was it due to specific symptoms?

  16. Elimination Diet Based on: • Detailed medical history • Analysis of Exposure Diary • Any previous allergy tests • Foods suspected by the patient • Formulate diet to exclude all suspect allergens and intolerance triggers • Provide excluded nutrients from alternative sources • Duration: Usually four weeks

  17. Selective Elimination Diets • Certain conditions tend to be associated with specific food components • Suspect food components are those that are probable triggers or mediators of symptoms • Examples: • Eczema: Highly allergenic foods • Migraine: Biogenic amines • Urticaria/angioedema: Histamine • Chronic diarrhea: Disaccharides • Asthma: Cyclo-oxygenase inhibitors Sulphites • Latex allergy: Foods with structurally similar antigens to latex • Oral allergy syndrome: Foods with structurally similar antigens to pollens

  18. Basic Hypoallergenic (“few foods”) Elimination Diet • Only listed foods are allowed • Nutritionally incomplete • Followed for maximum 10 days • GRAINS: White rice Tapioca • FRUITS: Pears; pear juice Cranberries; cranberry juice • VEGETABLES: Squash (all varieties) Carrots Parsnips Lettuce • MEAT: Lamb Wild game Turkey

  19. Basic Hypoallergenic (“few foods”)Elimination Diet (continued ) • MEAT Lentils SUBSTITUTES: Split peas Garbanzo beans (chick peas) • FLAVOURINGS: Sea salt • BEVERAGES: Distilled water in glass containers • OILS Canola oil or olive oil Safflower oil • OTHER Agar-agar (Make jelly dessert with pears and pear juice)

  20. Expected Results of Elimination Diet • Symptoms often worsen on days 2-4 of elimination • By day 5-7 symptomatic improvement is experienced • Symptoms disappear after 10-14 days of exclusion

  21. Challenge • Double-blind Placebo-controlled Food Challenge (DBPCFC) • Lyophilized (freeze-dried) food is disguised in gelatin capsules • Identical gelatin capsules contain a placebo (glucose powder) • Neither the patient nor the supervisor knows the identity of the contents of the capsules • Positive test is when the food triggers symptoms and the placebo does not

  22. Challenge (continued) • Drawback of DBPCFC • Expensive in time and personnel • Capsule may not provide enough food to elicit a positive reaction • May be other factors involved in eliciting symptoms, e.g. taste and smell

  23. Challenge (continued) • Single-blind food challenge (SBFC) • Supervisor knows the identity of the food; patient does not • Food is disguised in a strong-tasting “inert” food tolerated by the patient: • lentil soup • apple sauce • tomato sauce

  24. Challenge Phase continued • Open food challenge • Sequential Incremental Dose Challenge (SIDC) • Each food component is introduced separately • Starting with a small quantity and increasing the amount according to a specific schedule • This is usually employed when the symptoms are mild, and the patient has eaten the food in the past without a severe reaction Any food suspected to cause a severe or anaphylactic reaction should only be challenged in suitably equipped medical facility

  25. Open Food Challenge • The basic elimination diet, or therapeutic diet continues during this phase • If an adverse reaction to the test food occurs at any time during the test STOP. Do not continue to eat the test food • Wait 48 hours after all symptoms have subsided before testing another food

  26. Incremental Dose Challenge Day 1: Consume test food between meals • Morning: Eat a small quantity of the test food Wait four hours, monitoring for adverse reaction If no symptoms: • Afternoon: Eat double the quantity of test food eaten in the morning Wait four hours, monitoring for adverse reaction If no symptoms: • Evening: Eat double the quantity of test food eaten in the afternoon

  27. Incremental Dose Challenge (continued) Day 2: • Do not eat any of the test food • Continue to eat basic elimination diet • Monitor for any adverse reactions during the night and day which may be due to a delayed reaction to the test food

  28. Incremental Dose Challenge (continued) Day 3: • If no adverse reactions experienced • proceed to testing a new food, starting Day 1 • If the results of Day 1 and/or Day 2 are unclear : • Repeat Day 1, using the same food, the same test protocol, but larger doses of the test food Day 4: • Monitor for delayed reactions as on Day 2

  29. Sequential Incremental Dose Challenge • Continue testing in the same manner until all excluded foods, beverages, and additives have been tested • For each food component, the first day is the test day, and the second is a monitoring day for delayed reactions

  30. Sequence of TestingMilk and Milk Products Test 1: Casein proteins Test 2: Annatto, biogenic amines, plus casein Test 3: Casein plus whey proteins Test 4: Lactose in addition to casein and whey proteins Test 5: Modified milk components Test 6: Whey proteins (lactose-free) Test 7: Lactose (in whey) Test 8: Complex milk products (e.g. ice cream)

  31. Sequence of Testing:Wheat Test 1: Pure cereal grain Test 2: Wheat Cracker without yeast Test 3: White Bread Test 4: Whole Wheat Bread

  32. Sequence of Testing:Rye Rye: Test as for wheat: • Test 1. Rye Flakes (cooked) • Test 2. Rye Cracker (Ryvita™ (wheat-free) or Wasa™ (light) • Test 3. Rye Bread (100% rye flour, wheat-free)

  33. Sequence of Testing:Corn • Test 1:pure grain • corn-on-the-cob • frozen corn niblets: • Test 2:corn oil • added to tolerated food • Test 3: corn syrup • added to tolerated food

  34. Sequence of Testing:Alcoholic beverages • Test 1. Distilled alcohol (tequila; vodka; gin; white rum) • enhanced antigen uptake • Test 2. White wine • biogenic amines, especially histamine • Test 3. Red wine • biogenic amines, especially tyramine • Test 4. Beer, ale, lager • fermented grains • Test 5. Cider • fermented apple, pear, peach, etc.

  35. Sequence of Testing:Chocolate • Test 1 : Unsweetened (“bitter”) baker’s chocolate • Melt and add honey (if tolerated) as a sweetener • Solidify on a flat surface (e.g. baking sheet) • Break into squares • Test: 1, 2, 4 squares • Test 2: Purchased chocolates

  36. Maintenance Diet

  37. Final Diet • Must exclude all foods and additives to which a positive reaction has been recorded • Must be nutritionally complete, providing nutrients from non-allergenic sources • A rotation diet may be beneficial when the condition is due to dose-dependent food intolerance • There is no indication of any benefit from a rotation diet in the management of food allergy

  38. Important Nutrients in Common Allergens Equivalent nutrients must be provided from alternative sources when the following foods are eliminated from the diet: Milk and Milk Products: Calcium Riboflavin Smaller amounts: Phosphorus Potassium Vitamin A* Vitamin D* Vitamin E Vitamin B12 Pantothenic acid *Usually added as fortification to the food product

  39. Important Nutrients in Common Allergens Egg: Vitamin B12 Folacin Smaller amounts: Vitamin D Riboflavin Vitamin A Pantothenic acid Selenium Vitamin E Biotin Iron Vitamin B6 Zinc

  40. Important Nutrients in Common Allergens Wheat: Thiamin* Smaller amounts: Riboflavin* Magnesium Niacin* Folacin Iron* Phosphorous Selenium Molybdenum Chromium Rice: Thiamin* Niacin* Riboflavin* Iron*

  41. Important Nutrients in Common Allergens Peanut: Niacin Magnesium Smaller amounts Pantothenic acid Manganese Folacin Vitamin E Chromium Biotin Vitamin B6 Copper Phosphorous Potassium Soybean: Thiamin Folacin Phosphorous Riboflavin Calcium Magnesium Vitamin B6 Iron Zinc

  42. Important Nutrients in Common Allergens Fish and Shellfish: Niacin Phosphorous Vitamin B6 Calcium (in shellfish and fish bones) Vitamin B12 Selenium Vitamin E Smaller amounts: Potassium Iron Vitamin A Magnesium Zinc

  43. Current Areas of Research Promotion of Tolerance to Foods Probiotics and Food Allergy

  44. Recommendations for Introduction of Solids to High Risk for Allergy Infants • Most recent US consensus document recommends for infant at risk for allergy: • Exclusive breast-feeding from birth to six months • Optimal age for introduction of solids is six months • Dairy products introduced at 12 months • Eggs at 24 months • Peanut, tree nuts, fish, seafood delayed until at least 36 months __________________ Fiocchi et al July 2006

  45. Pregnancy Diet and Fish Intake 2006 study • Frequent maternal intake (2–3 times/wk or more) of fish reduced the risk of food sensitizations by over a third • A similar trend (not significant) was found for inhalant allergies • In the whole study population, i.e. allergic group plus non-allergic group: correlation between increased consumption of fish and decreased prevalence of SPT positivity for foods • Reduced incidence of allergic sensitization thought to be due to the omega-3 content of fish _______________ Calvani et al 2006

  46. Recent Evidence for Early Introduction of Solids? • “Delaying initial exposure to cereal grains until after 6 months may increase the risk of wheat allergy”1 • Based on questionnaires and parental report of wheat allergy • Excluded children with celiac disease • 16 children reported to have wheat allergy by parents • Four had wheat-specific IgE • These four were reported to have been first exposed to wheat grains after 6 months of age Previous studies: • “The possibility of cereal allergy after the introduction of cereal formula during the lactation period should not be underestimated”2 ________________ 2Armentia et al 2002 _________________ 1Poole et al June 2006

  47. Introduction of Solid Foods in Relationship to Celiac Disease Concept of “window of opportunity” • Research suggests that high risk for celiac disease occurs if gluten-containing grains are introduced before 3 months or after 7 months • Final conclusions: • “Current infant feeding practices should not be changed” _______________ Norris et al 2005

  48. Development of Tolerance • 25% of infants lost all food allergy symptoms after 1 year of age • Most infants will outgrow milk allergy by 3 years of age, but may have become intolerant to other foods in the meantime • Tolerance of specific foods : After 1 year: • 26% decrease in allergy to:  Milk Soy  Peanut  Egg  Wheat • 2% decrease in allergy to other foods ________________ Bishop et al 1990

  49. Prognosis Age at which milk was tolerated by milk-allergic children: • 28% by 2 years of age • 56% by 4 years of age • 78% by 6 years of age • About 25% of allergic children develop respiratory allergies • Allergy to some foods more often than others persists into adulthood:  Peanut Tree nuts  Shellfish  Fish

  50. Progression of Peanut Allergy • Peanut allergy, like many early food allergies, can be outgrown • In 2001 pediatric allergists in the U.S. reported that about 21.5 per cent of children will eventually outgrow their peanut allergy1 • Those with a mild peanut allergy, as determined by the level of peanut-specific IgE in their blood, have a 50% chance of outgrowing the allergy2 • Only about 9% of patients are reported to outgrow their allergy to tree nuts3 __________________ 1Skolnick et al 2001 2Fleischer et al 2003 3Fleischer et al 2005

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