Food allergy ,


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clinical presentation,diagnosis,treatment of food allergy
allergy&immunology unit,ain shams faculty of medicine
prof.fawzia abo ali

Published in: Health & Medicine

Food allergy ,

  1. 1. Fawzya abo aliProf. of int.medicine & allergyAin shams faculty of medicine
  2. 2. Emily’s StoryEmily Vonder MeulenBorn 1992 Eczema immediatelypresent on much of herbody Peanut Allergy at 2 yearsold Diagnosed with Asthmaaround 10 years
  3. 3. April 2006, one month from 8thgrade graduation and from her 14thbirthdayshe went shopping for graduation dress Emily was at a Cincinnati restaurantwhere she ordered a chicken sandwich. Catrina,the mother said ,we orderedaround 2:50and were done eating about3:10 But, about 10 minutes after shefinished it, she struggled to breathe.I called 911 at 3:26 but it was toolate.The doctor’s pronounced her dead at4:20 from anaphylaxis.
  4. 4. What is food allergy?What is food allergy? Food allergy is one of the adversereactions to food ,defined as: anabnormal response to food, mediatedvia the immune system.
  5. 5.  Epidemiology: Approximately 8% of children and 1-6% of adultssuffer from true food allergies.
  6. 6. Pathophysiology GI tract forms a barrier to outside environment GALT inhibits responses to non-dangerous antigenswhile mounting responses to pathogens Intact food antigens may penetrate the GI tract butnot cause clinical symptoms Develop in genetically predisposed individuals whenoral tolerance fails Increased intestinal permeability to macromolecules ; – Viral gastroenteritis, premature birth, cystic fibrosis – Leaky gut syndrome (LGS)
  7. 7. Foundation for Integrated MedicineImmunologic Mechanisms ofFood allergy Type I (IgE mediated, TH2 promoted) Type II (IgG and complement mediated,cytotoxic, TH1 promoted) Type III (IgG immune complex mediated,TH1 promoted) Type IV (cell-mediated, TH1 promoted)
  8. 8. IgE Mediated food reactionsCutaneous Urticaria &Angioedema Morbilliform rashes,FlushingGastrointestinal oral allergy syndrome Vomiting and diarrheaRespiratory Upper Ocular pruritus and tearing Lower Bronchospasm/wheezingGeneralized Anaphylactic shock
  9. 9. Non-IgE MediatedType II: Antibody dependent cytotoxicity Specific antibody binds to a surface tissueantigen and Milk-induced thrombocytopeniaType III: Antigen-antibody complex mediated Can be found in sera of normal patients&in patients with food hypersensitivity Little support for causing disease
  10. 10. Type IV: Cell-mediated hypersensitivityMediated by sensitized CD4+ T lymphocyteswhich process antigens and release cytokines . the reaction mediated through macrophagesbegins in hrs but reaching a peak in 2 to 3 days.
  11. 11. Sympt. Of delayed food allergyCutaneous Contact dermatitis,eczema Dermatitis herpetiformisGastrointestinal Food protein-induced enterocolitis Food protein-induced proctocolitis Food protein-induced enteropathy Celiac diseaseRespiratory (Heiner syndrome) asthma
  12. 12. Mixed IgE and Cell Mediated Atopic dermatitis Allergic eosinophilic esophagitis Allergic eosinophilic gastroenteritis Asthma
  13. 13. SoyCow’s milk Peanut Tree nutsFish ShellfishEgg whiteWheat
  14. 14. Food Allergen Proteins Cow milk β-lactoglobulin Egg yolk Lipoprotein Peanuts Peanut I + others Soybeans Glycinin + others Codfish Allergen M Green peasAlbumin Rice Glutelin/globulins Tomatoes Glycoproteins
  15. 15. Fatal Food-Induced AnaphylaxisAccounts for 1/3 of all anaphylaxis seen inemergency rooms Symptoms:generalized Dx by history and demonstration of food specific IgE Most were adolescents or young adults History of prior reaction to implicated food Only 10% had epinephrine available Peanuts and tree nuts for majority (94%)
  16. 16. Exercise-Induced Anaphylaxis (EIA) Rare form occurring when patientexercises 2-4 hrs after ingestion ofspecific food Without exercise, food no problem Most common in women prior tomenstruation Dx based on history and evidence ofspecific IgE Common offenders: wheat, shellfish,fish, fruits, milk
  17. 17. Celiac Disease
  18. 18. Food diary(DBFC)SPTPatchDiagnosis of Food Allergy
  19. 19. Skin prick testing
  20. 20. Treatment of food allergy Treat the reaction Avoid the food:The only proven treatmentfor a food allergy is to avoid the food. Read food labels OIT and SLIT show great promise, and awidespread treatment for food allergy maybe within reach. probiotics