Food Allergies and Intolerances: A Dieticians Role. Sareena Smith Spring 2010

Transcription

1 Food Allergies and Intolerances: A Dieticians Role Sareena Smith Spring 2010

2 Overview! Allergy vs. Intolerances! Food Allergies & Symptoms! Food Intolerances & Symptoms! Diagnosis and Treatment! Research Studies! Counseling Techniques! Counseling Role Play

3 Food Allergy vs. Intolerance! A food allergy is an immunologically based abnormal response to a food.! An intolerance is the inability to properly metabolize or absorb a substance.! The immune system plays no role in food intolerances.

4 Top 8 Food Allergies responsible for 90% of reactions! Wheat! Dairy! Eggs! Soy! Peanuts! Tree Nuts! Almonds, Hazelnuts, Walnuts, Brazil Nuts! Fish! Shellfish! Crab, Crayfish, Lobster, Shrimp

5 Other Top Allergens! Some fruits! Some vegetables! Seeds! sesame seeds! sunflower seeds! cottonseed! poppy seed! mustard seed! Chicken

6 Food Allergies! 1 in 3 Americans claim they have a food allergy.! Affects only 1-2% of the adult population.! Affects 3-7% of the pediatric population.! Two Types:! Immediate Onset IgE Mediated! Delayed Onset IgG Mediated! 80-90% of children outgrow their food allergies between age 5-15.! Nuts & fish 20% chance! Milk & Eggs 80%

7 Immunoglobulin E (IgE) based Allergic Reactions! An inherited predisposition to the allergy produces IgE antibodies in response to proteins that cross the gastrointestinal lining into the bloodstream when not broken down. The IgE then attaches to mast cells.! With any following exposures to the food, a reaction with the IgE and the allergen occurs and the mast cells release chemical mediators (i.e., histamine, tryptase) producing physical symptoms.

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9 Immediate (IgE) Food Allergy Symptoms! Reaction time: immediate to a couple hours! Reaction to a few, specific foods! Even small amounts can cause reaction! Reaction varies in degree of severity:! Asthmatics have severe reactions! Influenced by location of histamine release! Throat, nose, ears: itching, breathing, swallowing! Gastro-Intestinal: abdominal cramps, vomitting, diarrhea! Skin: hives or eczema

10 Food-Initiated Anaphylaxis! Whole body reaction! Lungs major target! Constriction of airways from histamine release! Difficulty breathing! Blood vessel dilation! Lowers blood pressure! Fluid leakage into tissues! Shock, hives, GI symptoms! Responsible for approx. 1,500 deaths in US each year! Immediate Treatment! Subcutaneous/ Intramuscular Epinephrine! Intravenous fluids! Medical Alert Bracelet

11 Immunoglobulin G (IgG) based Allergic reactions! Multiple foods causes allergic reactions! Usually 3-10 food allergens involved! Larger amounts of foods needed to initiate symptoms! Affects any system, organ or tissue of the body, in addition to common allergic reaction symptoms! Symptoms occur after several hours! Up to 72 hours later have been reported! Commonly reversible with 3-6 months of avoidance

12 Eosinophilic Esophagitis (EE)! EE is a relatively new allergic inflammatory disease characterized by inflammed and elevated levels of eosinophils in the esophagus! Present acid reflux symptoms, but not responsive to acid blocking medication! Misdiagnosis due to decreased awareness and other common diseases where eosinophils present in esophagus! GERD, IBD, food allergies! Commonly triggered by certain foods! Immediate or Delayed reactions Images courtesy of Dr. Chris Liacouras, Children s Hospital of Philadelphia.

13 Food Intolerances! An intolerance is the inability to properly metabolize or absorb a substance.! Caused by a variety of different reasons! Lacking sufficient enzymes! Lactase most common affecting 10% of the pop.! Bacteria degrade sugars that person cannot.! Histamine in Food! Found in some wines, some fish (tuna and mackerel), and cheese.! Food Additives! Yellow Dye #5, MSG, sulfites

14 Food Intolerance Symptoms! Lactose Intolerance! Gas formation, bloating, abdominal pain, diarrhea! Yellow Dye #5! Hives! Sulfites! Irritated lungs, severe bronchospasm in people with asthma! Monosodium Glutamate (MSG)! Flushing, warm sensations, headache, facial pressure, chest pains, feelings of detachment

15 Food Allergy and Intolerance Diagnosis Four Step Process - First Step! Complete physical exam! Detailed patient history! Timing! Food preparation! Portion size! Etc.! Detailed food records! With symptoms list and above information! Differential Diagnosis! Contaminated food resulting in food poisoning! Food Aversions! Intolerance due to psychological trigger! Similar diseases that share symptoms! Ulcers! CA of GI

16 Elimination Diet- Second Step! Elimination of suspected foods for 2 weeks - months! Suspect foods are added back 1 at a time until symptoms occur or normal levels are reached! Importance of compliance! Remains of food intake stay in body for up to a couple weeks! Can provoke clinical allergy for 2-10 days post consumption! Limitations! High patient motivation and compliance needed! Can be very arduous! Safety concerns! Cannot be used in patients with severe reactions! Adequate nutrient intake

17 Degree of Elimination Diets! Cereal-Free Elimination Diet! Fruit-Free, Cereal-Free Elimination Diets! Single Ingredient Elimination Diets! Minimal Elimination Diets! g Protein! kcals! Vitamin supplementation! Elemental Formula

18 Skin Tests Third Step! To be done by trained allergist! 95% predictive negative!! Good for narrowing possible allergens Only 50% predictive positive! Scratch Skin Test (IgE)! Dilute skin extract placed on skin of back or forearm! Scratched with needle observed for reactions Positive reaction indicates IgE on mast cells to specific food tested. Cannot be used with extreme reactions such as anaphylaxis or severe eczema!!

19 ! Patch Testing! Patches with small amount of allergen taped on back! Left on for hours! Useful for delayed onset allergic reactions! Skin Prick-Puncture Tests! Radioallergosorbent tests (RAST) - IgE! CAP System flourescent-enzyme immunoassay (FEIA)! Enzyme linked Immunoassay (ELISA) - IgG! Top layer of skin pricked with food extract! Blood is tested for antibdies

20 Food Challenges Final Step! To be done in a controlled setting with trained professional! Certified Allergist and Dieitian! Double-Blind, Placebo Controlled Food Challenge is now Gold Standard (DBPCF)! Done as open, single, or double blinded, placebocontrolled studies! Suspected allergen is hidden in food or capsule! Reaction to only one food confirms diagnosis! High risk : requires trained emergency personnel and medication present! Epinephrin, antihitamines, bronchodilators

21 Future in Treatment! Denaturization! Cooking or processing usually denatures allergen s protein.! Desensitization! Injections of small quantity of allergen extract! On a regular basis for a long period of time

22 General Approach to Food Allergies S.T.I.R.! Suspect! Test! Identify Foods, Interpret Testing, Initiate Treatment Plan! Re-evaluate and Re-introduce sensibly, seasonally! Before intense Elimination Diets are used, it is important to go through all Diagnosis steps

23 Food Allergies in Children Affect Nutrient Intake and Growth Lynn Christie, MS, RD; R. Jean Hine, PhD, RD; James G Parker, MS; Wesley Burks, MD

24 ! Objective! To identify if food allergies, elimination diets or other related variables have an affect on the growth and nutrient intake of children with food allergies.! Subjects! 197 children: 98 with allergy, 99 without! Age matched (1 mo-10 years old), consecutive sampling, cross-sectional study! Allergy diagnosis confirmed after positive skin prick test, IgE antibody test, food challenge, and food elimination diet followed.

25 ! Parameters! BMI, height-for-age, weight-for-age taken and put into 3 categories:! less than 25 th percentile : potential undernutrition! 25 th -75 th percentile: adequate nutrition! Over the 75 th percentile: potential overnutrition! Evaluated by Cochran-Mantel-Haenszel Statistics with General Association! Methods! Detailed Dietary Intake Record instructions were given! Each record verified to resolve any omissions or ambiguities! Analysis and estimated energy needs based on 10 th edition of RDAs! Estimated vitamin and mineral needs based on DRIs and AIs - <67% indicates need for improved consumption

26 Results More children with food allergies were <25 th percentile heightfor-age (n=27 vs 16) 2/3 of food allergy group had atopic dermatitis A statistically significant (p<.05) more children with 2+ food allergies were <25 th percentile than those with only 1 food allergy (35% vs 16%)

27 ! Discussion! Nutrition complications with elimination diets are not well studied! This study suggests food allergies have a negative impact on growth and food intake! Atopic dermatitis is a concern for delayed growth in children! Adequate testing needed prior to food avoidance! Dietitian s Role! Counseling for appropriate alternatives, avoidance! Guidance for selection, information on identifying hidden ingredients! Significant improvement on nutrient intake from nutritional counseling! 1 mo post allergy diagnosis, 6 mo/annual visits

28 Food Perceived by Adults as Causing Adverse Reactions Sharon L. Parker, PhD, RD; Magdalena Krondi, PhD; Patricia Coleman, MSc

29 ! Objective! To identify differences in reaction patterns and offending foods reported by patients with classic allergy symptoms versus subjective foodrelated complaints! Participants! 45 patients with food related complaints being seen at an allergy clinic years old! 22 diagnosed with confirmed adverse food reactions! Positive skin tests, consistent with IgE-mediated food hypersensitivity reactions! 23 diagnosed with unconfirmed adverse food reactions! Neurological, GI, misc. symptoms

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31 ! Methods! Symptom and reaction pattern study was limited to 5 foods as a maximum to follow.! Avoid suspected foods starting 2 weeks before first food challenge through the duration of the study! To confirm food reactions:! Detailed patient clinical history! Skin Testing consisted of the prick-through- drop method! Double Blind Placebo controlled Food Challenge! Self- administered questionnaire with a list of 121 foods/food components to determine offending foods

32 Results 11.5% had a positive reaction to the food challenge Participants with confirmed reactions had a significantly significant fewer number of foods that caused symptoms during adulthood than those with unconfirmed reactions (P=.0002). Dietitian s Role Many people have reactions to foods that can be unconfirmed as an allergic reaction This group is at greater nutritional risk due to the higher number and nature of the offending foods They are also more likely to be vulnerable to nutritional misinformation due to what governs their food choices Flexibility and dedication by client and dietitian is key for improvement of symptoms

33 Counseling Techniques! A Dietitian s Role in Allergy Management---! Obtain Detailed, Patient History and Food & Symptoms diary including timing, food prep, and portion sizes! Providing clients with alternatives to reactive foods that will provide adequate nutritional intake and balance! Elimination Diets! A Multi-Disciplinary Health Care Team Approach with Trained Allergist

34 ! Awareness of cross contamination within household! Reading of food labels! Use Motivational Interviewing to determine fears, overcome barriers, and discover what drives food patterns and choices! Use Intuitive Eating to determine what foods make the body feel good

35 CrossSensitivities

36 ! Joanna, 35 year old female Role Play! Went to her PCP complaining of a food allergy! Has been to an allergist for Scratch testing with negative results to many common allergens! Was referred to dietitian to help implement an elimination diet to determine what is provoking her symptoms! This is her 2 nd visit with the dietitian! In the previous appointment Joanna was very frustrated about her negative allergy test results! Her goal was to eliminate one food that gives her bad reactions for the 2 weeks, until her next appt. with the RD

37 References 1. Nelms, M., Sucher, K., Long, S. Nutrition Therapy and Pathophysiology Thomas, Brooks/ Cole. 2. Merriam-Webster Online Dictionary TANG, A. M.D., A Practical Guide to Anaphylaxis. Fam Physician Oct 1;68(7): Book, Wendy. American Partnership for Eosinophilic Disorders. About EE Christie, L. et al. Food allergies in children affect nutrient intake and growth. Journal of the American Dietetic Association Nov.;102(11): Immuno Laboratories, Inc. Food Relief When you have allergic food reactions, do you know which kind Immediate or delayed? Better Health USA Cheng, L. MD, PhD. The Who, when, where and what of food allergies. Slides. UCSF Medical Center

38 References Cont d 8. Parker, S. et al. Foods perceived by adults as causing adverse reactions. Journal of the American Dietetic Association Jan.; 93(1): Dietitians face the challenge of food allergies. Journal of the American Dietetic Association Jan.; 100(1): National Institutes of Health. Public Health Service. Food allergy and intolerances. U.S. Department of Health and Humand Services April. 11. Rowe, A.H. M.D., Elimination diets and the patient s allergies Lea & Febiger 12. Rowe, A.H., MS, MD, Rowe, A. Jr., MD. Food allergy, It s manifestations and control and the elimination diets, a compendium Charles C Thomas Publisher