به نام خدا

1. به نام خدا

2. Management of Food Allergy By: TOOBA MOMEN Clinical Allergist & Immunologist

3. Adverse reactions to foods • Food intolerance (most common) • Food allergy (hypersensitivity) • Food aversion (phobia)

4. FOOD INTOLERANCE • It caused by factors inherent in food ingested: Enzyme Deficiency GI disorders Anatomical defect Physiological effects of Active Substances Food Additives & Contaminants Neurologic disorder

5. Food Allergy • An adverse health effect arising from a specific immune that occurs on exposure to a given food

6. Epidemiology of food allergy • Food allergy is on the increase in developed countries • Factors contributing to the epidemic appear to be related to the modern lifestyle but as yet are poorly understood. • The incidence of food allergy-related anaphylaxis, the most severe consequence of food allergy, is rising particularly in the under 4-year age group. • Overall more than 90% of food allergies in children are caused by cow’s milk, hen’s egg, soybean, wheat, peanut, tree nut, fish, and shellfish. → overall 8% • In adults sea food( 2.3%), peanut& tree nut(1.2%) → overall 3.5-4 %

7. Frequently allergenic foods • Most common food allergies in young children: • Milk (casein, whey) • Eggs • Wheat (gluten) • Soy • Peanuts • Tree nuts • Shellfish • Most common food allergies in older children & adults • Fish • Shellfish • Peanuts • Tree nuts

8. Pathophysiologic mechanisms of food allergy

9. Immediate <1 hour • Delayed >24 hours • Volume required for reaction

10. Manifestations of food allergy

11. cutaneous • IgE mediated: Urticaria, Angioedema Contact urticaria • Mixed IgE &non IgE mediated: Atopic dermatitis • Non IgE mediated: Contact dermatitis Dermatitis herpetiform

12. Gastrointestinl • IgE mediated: Acute gastrointestinal hypersensitivity pollen-food allergy syndrome • IgE & non IgE mediated: Eosinophilic esophagitis Allergic eosinophilic gastroenteritis • Non IgE mediated: Allergic proctocolitis food protein induced entrocolitis food protein induced enteropathy, celiac

13. respiratory • IgE mediated Allergic rhinoconjuctivitis Allergic bronchospasm • IgE & non IgE mediated: Asthma • Non IgE mediated Pulmonary hemosiderosis

14. Diagnosis & management of food allergy

15. HISTORY &PHYSICAL EXAMINATION • Food presumed to have provoked the reaction • Quantity of the suspected food ingested • Length of time between ingestion &development of symptoms • Whether similar symptoms developed on other occasions when the food was eaten • Whether other factors (exercise, alcohol, drugs) are necessary • How long since the last reaction to food occurred • Personal hx of atopy • Family hx of food allergy & atopy • Diet diaries

16. Diagnostic test

17. Skin prick test • Skin prick or puncture tests to foods are very useful when properly performed and interpreted. • Negative prick/puncture skin tests have a high negative • predictive accuracy for many foods (>95% for the common foods). • Positive prick/puncture skin tests have a high positive • predictive accuracy for egg, milk and peanut in young • children, and the size of the skin test is relatively • predictive. • A negative test with a suspicious history requires a • food challenge before the food is returned to the diet

18. Invitro test for specific ige • Food specific IgE exceeding the diagnostic values indicate that patients are more than 95% likely to experience allergic reaction after ingestion of specific food PREFERENCE FOR IN VITRO TESTS VS SKIN TESTS • Patients with extensive dermographia • Patients with extensive atopic dermatitis or generalized urticaria • Patients who cannot discontinue antihistamines • Areas where there are no allergists to perform skin testing

19. Oral Food Challenge Procedures • Oral food challenges (particularly double-blind placebo-controlled food challenge) represent the accepted gold standard investigation for objective diagnosis of both immediate and delayed-onset food allergy. • Oral food challenges are clinically indicated to demonstrate allergy or tolerance to achieve safe dietary expansion or appropriate allergen avoidance

20. Challenge • Double-blind Placebo-controlled Food Challenge (DBPCFC) • 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 when the placebo does not

21. Challenge continued • Single Blind Food Challenge • Supervisor knows the identity of the food • Food is disguised in strong-flavoured food e.g. apple sauce; lentil soup • Open Food Challenge • Sequential incremental doe challenge (SIDC) • Determines sensitivity and dose tolerated for each eliminated food in its purest form

22. Indication for ofc

23. Indicative of IgE MEDIATED

24. INDICATIVE OF CELL MEDIATED OR MIXED MECHANISM

25. Food allergen avoidance strategies

26. Should be prescribed based on confirmed diagnosis • Some times strict avoidance in not necessary -extensively heated product for egg or milk allergy - maternal ingestion of allergen while breast feeding - raw fruit & vegetables causing oral symptoms • Labeling of manufactured product • Cross contact

27. Labeling

28. Manner of exposure • Skin contact • Inhalation • Ingestion

29. Examples of food allergens in unexpected and nonfood items • Cosmetics almond or milk in shampoos or ointments • Pet food milk, egg, fish, soy • Medications lactose in DPI or tablet , soy lecithin • Vaccines egg(influenza, yellow fever), milk(DPT) • Nutrition supplements glucosamine chondrotin supplements(shark cartilage or shrimp shell) • Saliva(kissing) residual protein from meals • Transfusion containing allergen from donor ingestion

30. Natural history of food allergy • Most young children outgrow their food sensitivity within a few years except in most cases of peanut, tree, and seafood

31. Milk Allergy: most of them become tolerant till 3y/o, 50% by 1y/o, 70% by 2 y/o, 85% by 3 y/o • Egg Allergy: 66% become tolerant by 5 y/o • Peanut Allergy: 20% become tolerant with age • Tree nut Allergy : 9% become tolerant with age

32. Emergenciymanagment • Prompt recognition of reaction • Treatment with epinephrine and antihistamines • Emergency plans and special considerations for schools

33. Food allergy prevention

34. Changes in notions about allergy prevention through diet

35. Future therapeutic strategies • Strict avoidance of allergens is not curative and leaves patients at risk for accidental exposure. As such, several new therapeutic approaches are being tested in clinical trials.

36. Allergen non specific therapies • Humanized monoclonal anti- IgE • Traditional Chinese Medicine • Probiotics &Prebiotics

37. Allergen specific immunotherapy • Oral immunotherapy • Extensive heated milk & egg proteins • Sublingual Immunotherapy • Epicutaneous Immunotherapy • Modified or recombinant allergen immunotherapy

38. summary • Current therapy for food allergy requires education about avoidance in a variety of setting & instruction on when &how to treat inevitable allergic reactions • Current therapeutic strategies are focused on harnessing oral tolerance to modulate allergic response using Ag-specific & non specific approaches.

39. Thank you for your attention