Food F or Thought

1. Food For Thought Jeff Lehman, MD Illinois WIC Conference April 24, 2014

2. Definitions

3. Food Allergy (FA) • An adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food.

4. Food Intolerance (FI) • Non-immunologic mechanism that involves the digestive system and is not always reproducible since many affected patients can tolerate small amounts of culprit food without symptoms.

5. Food Allergens • Specific components of food or ingredients within food (typically proteins, but sometimes also chemical haptens) that are recognized by allergen-specific immune cells and elicit specific immunologic reactions, resulting in characteristic symptoms.

6. Adverse Food Reactions Non-immunologic(primarily food intolerance) Metabolic (eg, lactose intolerance) Pharmacologic (eg, caffeine) Toxic (eg, scombroid fish toxin) Idiopathic (eg, sulfites) Adapted from Boyce et al. J Allergy ClinImmunol2010;126:S1-58.

7. Adverse Food Reactions Immunologic IgE mediated (eg, acute urticaria, oral allergy syndrome) Non-IgE mediated (eg, food protein-induced enteropathy, celiac disease) Mixed IgE & non-IgE (eg, eosinophilic gastroenteritis) Cell Mediated (eg, allergic contact dermatitis) Adapted from Boyce et al. J Allergy ClinImmunol 2010;126:S1-58.

8. Prevalence • True prevalence of FA difficult to establish • 170 foods reported to cause allergy, but prevalence studies focus on most common foods. • Studies of FA incidence, prevalence and natural history are difficult to compare because of inconsistencies and deficiencies in study design and variations in definition of FA.

9. Prevalence Rona RJ et al. The prevalence of food allergy: a meta-analysis. J Allergy ClinImmunol 2007. 120(3):638-46.

10. Prevalence Zuidmeer L et al. The prevalence of plant food allergies: a systematic review. J Allergy ClinImmunol 2008. 121(5):1210-8.

11. When should food allergy be suspected? • Anaphylaxis or combination of symptoms that occur within minutes to hours of ingesting food • Infants, young children and selected older children diagnosed with certain disorders such as: moderate to severe atopic dermatits/eczema, Eosinophilic GI disorders, protein induced enterocolitis

12. Clinical Presentation • Rapid onset (minutes to 2 hours) • Urticaria/Angioedema • Rhinoconjunctivitis • GI anaphylaxis • Generalized anaphylaxis • Oral allergy syndrome (OAS) • Food dependent exercise induced anaphylaxis • Associated conditions • Atopic dermatitis • Asthma

13. Urticaria/Angioedema • Most common cutaneous manifestation • Acute (< 6 wks)=most common manifestation (~20% acute urticaria due to foods) • Chronic (> 6 wks)- food uncommon

14. Rhinoconjunctivitis • Common component • Conjunctival injection, lacrimation, periorbitaledema, pruritus • Isolated symptoms rare

15. GI anaphylaxis • Nausea • Vomiting • Abdominal pain • Abdominal cramping • Diarrhea Minutes to 2 hrs 2 to 6 hrs

16. Generalized anaphylaxis • Food causative in 50% ER treated • Most common: • Peanuts, tree nuts, fish, and shellfish

17. Oral allergy syndrome (OAS)(pollen-food allergy syndrome) • 50% pts with allergic rhinitis to pollen • Food protein cross reactive with pollen protein • Sxs more noticeable during pollen season • Confined to oropharynx (minutes) • pruritus, irritation, and mild swelling of the lips, tongue, palate, and throat • fresh, uncooked fruits and vegetables • Progression to systemic sxs=<10%; anaphylaxis=1-2%

19. Atopic dermatitis (AD) • ~40% infants with mod-severe AD have food allergies • Conversely, 27 % of children with food allergy are reported to have eczema or skin allergy vs. 8% of children without food allergy • Food-related exacerbations of AD involve both IgE-mediated and non-IgE mediated hypersensitivity

20. Atopic Dermatitis • Relationship between AD and food • Elimination of suspected food allergens frequently improves symptoms of AD • Repeated exposure to suspect foods commonly exacerbates skin symptoms • Eliminating foods to which an infant has demonstrable allergy can partially prevent the development of atopic dermatitis

21. Asthma • Isolated asthma uncommon • Exception: Occupational asthma • Baker’s asthma (inhaled wheat proteins)

22. Disorders Not Proven to be Related to Food Allergy • Migraines • Behavioral / Developmental disorders • Arthritis • Seizures • Inflammatory bowel disease

23. Non IgE-mediated • Lactose intolerance • Food protein-induced enterocolitis • Food protein-induced proctitis and proctocolitis • Celiac disease • Food-induced pulmonary hemosiderosis (Heiner's syndrome)

24. Lactose intolerance • Abdominal pain/cramping, bloating, flatulence, diarrhea, and vomiting • Intolerance to lactose-containing foods (primarily dairy products) is common • In Europe and the United States, the prevalence is 7 to 20% in Caucasian, 80 to 95% among Native Americans, 65 to 75% among Africans and African Americans, and 50% in Hispanics

27. Food protein-induced enterocolitis/proctitis • Cell-mediated • Infants <9 months (1wk-3months) • Cow's milk or soy, although oat, rice, and poultry are other causative foods • Rare when solely breastfed • Vomiting, diarrhea, malabsorption, or bloody stools • Resolution with restriction of causative food

28. Celiac disease • aka gluten-sensitive enteropathy or nontropicalsprue • triggering proteins are wheat, barley, and rye • Sxs: diarrhea, anorexia, abdominal distension and pain, and failure to thrive or weight loss • Skin manifestations • Dermatitis herpetiformis • Eczema • Epidermal necrolysis • Pityriasisrubra • Pustular dermatitis • Cutaneousvasculitis • Cutaneousamyloid

29. Celiac disease • Diagnosis • IgA (IgG) antibodies against tissue transglutaminase (anti-tTG), which is highly sensitive, specific, and most cost-effective • IgA (IgG) antibodies to endomysium • Small Intestinal Biopsy • Treatment • Gluten free diet for life resolution

30. Food-induced pulmonary hemosiderosis (Heiner's syndrome) • Recurrent pneumonia with pulmonary infiltrates, hemosiderosis, iron deficiency anemia, and failure to thrive • Infants • Cow's milk = most common causative food • pork and egg also reported • IgG to cow’s milk protein • Removal of food resolution

31. Eosinophilicesophagitis (EoE) • Any age • Children may present with feeding disorders • Older children and adults present with dysphagia, vomiting, and abdominal pain (A history of food impaction is common) • Failure to respond to antacids and antireflux therapies is an important aspect of the history

32. EoEcontinued • In a retrospective review of 381 children with EE: • most commonly implicated foods = cow's milk, egg, soy, corn, wheat, and beef • Elimination of these foods or the use of elemental diets results in clinical and histologic improvement in most • However, the pathophysiologic relationship between this disorder and food and aeroallergens remains unclear

33. Summary • The DDx = non-immunologic and immunologic disorders • IgE-mediated food allergy typically develops rapidly after food ingestion, ie, usually within minutes • Symptoms can affect multiple organ systems cutaneous reactions (urticaria, angioedema), rhinoconjunctivitis, gastrointestinal anaphylaxis, generalized anaphylaxis, the oral allergy syndrome, and food-dependent, exercise-induced anaphylaxis • Atopic dermatitis &asthma are atopic conditions in which food allergy may play a role in some patients, but is not the sole pathogenic process • Non-IgE-mediated food reactions present as more subacute and/or chronic symptoms, which are more commonly isolated to the gastrointestinal tract • food protein-induced enterocolitis • food protein-induced proctitis/proctocolitis • celiac disease • food-induced pulmonary hemosiderosis (Heiner's syndrome) • Eosinophilicesophagitis and gastroenteritis

50. Diagnostic Tools (IgE mediated) • Clinical history is critical in the diagnosis • Prick/puncture skin testing • In vitro testing • Food challenge • Food elimination diets Must always be interpreted in the context of clinical history