Module 5: Food Allergies and Intolerances

A Preschool Nutrition Primer for Dietitians Module 5: Food Allergies and Intolerances Slide 1: A Preschool Nutrition Primer for Dietitians Module 5: Food Allergies and Intolerances The Nutrition Resource Centre and NutriSTEP present Food Allergies and Intolerances. This training module is one of five topics to increase the knowledge, skills and competence of Registered Dietitians who work in a variety of care settings. The goal of these evidence-informed Primers is to increase your comfort level to provide quality nutrition services to your clientele and support team-based care of young children. Slide 2: Learning Objectives for this presentation are to: Distinguish food allergy from other adverse food reactions. List the nine common food allergens according to Health Canada. Understand medical diagnosis and management of food allergy (including symptoms and tests) in order to communicate effectively with the client and attending physician. Understand the appropriate dietary management of food allergy, including allergen avoidance and ensuring nutritional adequacy. List high-risk situations for allergic individuals. List strategies for avoiding allergenic proteins in foods. Slide 3: Presentation Outline will include the following topics: Introduction to Food Allergies Allergy versus Intolerance The Immune System Reactions to an Allergen Diagnosis of a Food Allergy Managing Food Allergies Prevention/Delaying Allergic Disease Health Canada Regulations on Allergen Food Labeling and References Slide 4: Introduction to Food Allergies An allergy is also known as hypersensitivity It is an Immune system response to the protein in foods And the Body recognizes the protein as a foreign substance and produces a number of responses (called allergic reactions) 1 NutriSTEP (June 2010) 1

Module 5: Food Allergies and Intolerances A Reaction is not dose dependent The Common food allergies in children are: eggs, soy, milk, wheat, seafood (including shellfish, fish), peanuts, tree nuts, and sesame (sulphites) While the Common food allergies in adults are: peanuts, tree nuts, shellfish, and fish Slide 5: Statistics of Food Allergies Nearly 4% of North Americans have food allergies, many more than recorded in the past The incidence of food allergy much higher in children (>8%) than adults (<2%) The prevalence of some food allergies doubled in American children younger than 5 years of age in the past 5 years Many food allergens have been characterized at the molecular level, leading to increased understanding of the causes of many allergic disorders Slide 6: Incidence of Food Allergy The prevalence is highest in infants and toddlers Cow s milk allergy incidence: is 2.5% of infants Up to 8% of children under 3 years have an allergy to a limited number of foods including: o Cow s milk o Wheat o Egg o Shellfish o Fish o Soy o Peanut o Tree nuts Slide 7: Incidence of Food Allergy Over 170 foods have been documented as causing food allergy 90% of food allergies in children are due to: milk, soy, peanut, egg and wheat 85% of food allergies in adolescents and adults are due to: peanut, fish, tree nuts, and shellfish 2 NutriSTEP (June 2010)

A Preschool Nutrition Primer for Dietitians Slide 8: Priority Food Allergens in Canada This list contains the top allergic foods and account for more than 95% of severe adverse reactions related to food allergens. Slide 9: Allergy versus Intolerance This chart shows the differences between a food allergy and an intolerance. Generally, a food allergy is a sensitized, immune response that is not dose dependent and is an inherited characteristic while a food intolerance is an abnormal physiological response that is dose dependent and may be inherited but not always. Slide 10 and 11: Examples of Food Intolerances include: Lactose, sucrose and sulphite intolerance MSG sensitivity, sensitivity to food additives and to biogenic amines such as Tyramine and Histamine Slide 12: What is Celiac Disease? It is a hypersensitivity to gluten, a protein found in wheat, barley, rye, and certain other grains, in which the immune system damages the villi of the small intestine and causes chronic inflammation. It is therefore both an autoimmune disorder and a disease of malabsorption. Dermatitis herpetiformis is a chronic skin disorder that may occur simultaneously with Celiac Disease or alone. It is associated with a specific immunogloben A- mediated immune sensitivity to gluten. Slide 13: Celiac Disease Celiac Disease symptoms are often confused with irritable bowel syndrome (IBS), iron-deficiency anemia, Crohn s disease, diverticulitis, intestinal infection, and chronic fatigue syndrome. Celiac Disease can produce gastrointestinal and/or skin symptoms. An individual with Celiac Disease may also be asymptomatic, therefore increasing the risk for malnutrition-related complications. Malnutrition as a result of Celiac Disease may cause weight changes, dental problems, fatigue, anemia, osteopenia/osteoporosis, behavioral changes, nerve damage, muscle cramps, seizures, ammenorhea, miscarriage, infertility, delayed growth, and/or failure to thrive in infants. NutriSTEP (June 2010) 3

Module 5: Food Allergies and Intolerances Slide 14: The Immune System Allergic reactions to foods may also be cell-mediated. While the pathogenesis of such reactions is not as clearly defined as IgE-mediated reactions, it is thought that T cells respond directly to the allergenic protein, acting with macrophages and other inflammatory cells to cause inflammation in the GI tract and skin. Slide 15: The Immune System All foods contain proteins derived from plants and animals all of which are foreign to the human body In order for food to be absorbed, metabolized, and utilized by the body, the immune system needs to be educated that the foreign material is safe This involves a complex series of immunological reactions Slide 16: The Immune System In most cases this results in education of the T cells to not respond to that food protein when it enters via the oral route called oral tolerance. This contrasts with the active immune responses needed to protect the gut against continual bombardment by invading pathogens and their products (such as toxins, etc). Slide 17: The Immune System Food allergy occurs as a result of a lack of tolerance T cells respond as if the food were a threat to the body Antibodies are produced specifically to reject the food and is called sensitization Inflammatory mediators are released to defend the body Mediators act on body tissues to cause the symptoms of allergy Slide 18: Inflammatory Chemicals in the Allergic Reaction Include histamine E, enzymes, Chemo-attractants, Prostaglandins and Leukotrienes. Each chemical has a different effect on tissues: the allergic response is the combined effect of them all. Slide 19: Symptoms of Food Allergy. This diagram shows the four points of reaction mouth, airways, gastrointestinal tract, and skin. 4 NutriSTEP (June 2010)

A Preschool Nutrition Primer for Dietitians Slide 20: Symptoms: GI Tract Food allergy symptoms may involve the gastrointestinal tract with symptoms such as swelling or itching of the lips, mouth and/or throat. Additionally, nausea, vomiting, cramping and/or diarrhea may occur. Eosinophilic esophagitis and gastroenteritis are disorders in which a white blood cell, the eosinophil, collects in gut tissues leading to symptoms such as pain with eating, possible obstruction, malabsorption, and poor growth. The disorders may be associated with IgE- and/or cell-mediated food allergic responses. Eosinphilic gastrointestinal disease often requires trial elimination diets. The registered dietitian can play a critical role in working with the physician and/or allergist to develop an elimination diet and counsel patients and families on adherence to the elimination diet, as well as nutritional adequacy of the diet. Slide 21: Symptoms: Skin The most common food allergy symptoms involve the skin, in the form of itching, swelling, hives, eczema and/or redness. Up to 20% of acute hives are caused by food allergy; while hives lasting more than six weeks are rarely caused by food allergy. 37% of children with moderate to severe atopic dermatitis also have food allergy. Slide 22: Symptoms: Respiratory Tract The upper and lower respiratory tract can be a target of IgE-mediated food allergy, with symptoms including congested, runny, and/or itchy nose (rhinitis), sneezing, raspy cough, and/or wheezing. Nasal symptoms occur in 25-80% of food allergic patients. However, nasal symptoms in isolation usually are not food-related. Asthma is food-related in only 5.7% of asthmatic children. Heiner Syndrome is a rare adverse pulmonary response to cow s milk that occurs in a very small percentage of infants. It is characterized by repeated pneumonia, and may result in irondeficiency anemia and even failure to thrive. Slide 23: Symptoms: Anaphylaxis Anaphylaxis is a serious allergic reaction. It can be life-threatening. Anaphylaxis affects multiple body systems: skin, upper and lower respiratory, gastro-intestinal and cardiovascular. Anaphylactic shock is an explosive overreaction of the body's immune system to a triggering agent NutriSTEP (June 2010) 5

Module 5: Food Allergies and Intolerances (allergen). It can be characterized by swelling, difficulty breathing, abdominal cramps, vomiting, diarrhea, circulatory collapse, coma and death. Slide 24: Symptoms: Anaphylaxis Food is the most common cause of anaphylaxis, but insect stings, medicine, latex, or exercise can also cause a reaction. The commonest food allergens are peanuts, tree nuts, seafood, egg and milk products. Approximately 1-2 percent of Canadians live with the risk of an anaphylactic reaction. Although anaphylaxis is most often diagnosed in childhood, it can also develop later in life. Living with anaphylaxis can be a challenge. People with this condition must learn how to avoid the allergen that causes their reaction. They must also be prepared to manage an unexpected reaction. Treatment is an Epinephrine (adrenaline) shot. Slide 25: Symptoms: Anaphylaxis Anaphylaxis is a growing public health issue Fatalities are rare and usually avoidable Measures must be in place to reduce the risk of accidental exposure and to respond appropriately in an emergency. These include: o Improved patient self management o Comprehensive school board policies o Standardized school anaphylaxis plans o Greater community support and involvement Slide 26: Diagnosis of a Food Allergy Is managed by primary care physician or board-certified allergist Includes complete medical history and physical exam May include a food diary, completed by the patient Screening Tools o Skin Prick Test o Blood Tests Diagnosing a food allergy may be straightforward if symptoms are consistent. However, since there can be many different components at work in food related illnesses, it is advisable that the patient see their 6 NutriSTEP (June 2010)

A Preschool Nutrition Primer for Dietitians primary care physician or a board-certified allergist to determine whether the symptoms are related to food allergy or another medical issue. The first step in diagnosing a food allergy is a thorough examination of the patient s medical history. A complete physical examination and selected laboratory tests may be conducted. The patient may be asked to keep a detailed food diary and record of symptoms, which may help to identify potential culprits. The dietitian can guide the patient in recording a useful food diary, detailing the amount of food that is eaten; the amount of time between food consumption and symptom development; how often the reaction occurs; and any other relevant information. Sensitization (the presence of food-specific IgE antibodies) is detected by a blood and/or skin prick test. The skin prick test involves introducing a small amount of allergen extract into the skin by making a small puncture. The specific allergens to which a patient is allergic will cause a reaction at the site of the test. Both of these tests are utilized to support a diagnosis of food allergy. It is also important to note that skin prick and blood tests are screening tools with high false positive rates and should be used in combination with medical history, elimination diet, and/or food challenge tests. Slide 27: Diagnosis of a Food Allergy An elimination diet, involves eliminating suspected foods from the diet for a period of time that varies according to the particular clinical manifestations that are present. If improvement is seen, then suspected foods may be reintroduced one at a time, possibly under direct medical supervision (e.g., a medically-supervised oral food challenge) if a risk of anaphylaxis or acute allergic reaction is possible, to disclose the problematic food(s). The double-blind, placebo-controlled oral food challenge is the gold standard diagnostic tool for food allergy. The food challenge involves physician-supervised consumption of increasing doses of the suspected food until the individual develops symptoms or tolerates a normal portion. A food challenge is not always necessary, such as when a severe reaction has clearly followed consumption of the suspected food. As with most health conditions, diagnosis involves both science and NutriSTEP (June 2010) 7

Module 5: Food Allergies and Intolerances clinical judgment by the attending physician. Clinical tolerance develops to most food allergens over time, although less frequently for peanuts, nuts, fish, and shellfish. Under the care of a board-certified allergist, children may be periodically reevaluated to determine if they have outgrown their allergy. Slide 28: Dietitian s Role The Registered Dietitian can play a role in caring for the food allergic individual. She or he can refer a patient to an allergist for evaluation. The dietitian may suspect food allergy in a patient, or receive a new patient who perceives that they have a food allergy. In either case, involving the allergist or primary care physician is critical for an appropriate diagnosis and treatment. She or he can also play an important role in supporting the physician/allergist during the diagnostic process by: helping the patient to complete a food diary, assisting with a physician-supervised food challenge, developing an elimination diet, and/or helping the patient to adhere to the elimination diet. Slide 29: Managing Food Allergy Once a food allergy diagnosis is made by the physician, effective management of food allergies consists of: 1) Avoiding allergen containing foods and high risk situations (discussed in greater detail in the following slides) 2) Developing a Food Allergy Action Plan The Food Allergy Action Plan is designed to recognize and treat potentially severe food allergic reactions. Food allergic patients should have a written emergency plan for treatment in the event of accidental ingestion of an allergen. Those judged to be at increased risk of anaphylaxis (for example those with asthma or a history of peanut, tree nut, or seafood allergies) should carry self-injectable epinephrine (adrenaline). Syringes with pre-measured doses of epinephrine are available by prescription. Oral antihistamines may be helpful in treating mild reactions, but early administration of epinephrine can be life-saving. Medical-alert bracelets or necklaces can also be worn to quickly alert EMS, medical personnel, or other caretakers if the food allergic person is found unconscious. 8 NutriSTEP (June 2010)

A Preschool Nutrition Primer for Dietitians Slide 30: Managing Food Allergy The registered dietitian can play a crucial role in helping the allergic patient to successfully avoid food allergens while maintaining both nutritional adequacy and quality of life. For infants, pinpointing offending proteins is a much simpler proposition. If the baby is fed with infant formula, the pediatrician may recommend a hypoallergenic formula. If the baby is breastfed, the mother may eliminate peanuts, tree nuts, milk, fish, and eggs from her diet as a proactive strategy. This action could have significant nutritional implications that can be managed with the help of the RD. The most important skill for an allergic child and his or her family is communication. Avoiding allergenic foods involves not only seeking information, but also sharing it with others who provide and prepare food. Common food allergens have previously been identified in this module. Slide 31: Managing Food Allergy The physician s diagnosis will identify the specific food protein(s) that must be avoided. The patient will look to the dietitian for assistance regarding less obvious foods and ingredients that may contain that allergen. For example, milk protein is found not only in milk, but also in cheese, yogurt, ice cream, butter, pudding, and particular sauces and other preparations. Reading food labels is challenging for some consumers, as the names of some ingredients that contain allergenic proteins may be unfamiliar to the average person. A complete list of common food allergens is available from Food Allergy & Anaphylaxis Network website. Carrying an injectable adrenalin, and being familiar with its use in case of accidental exposure reaction, can save one s life. Also, it is important to wear a MedicAlert tag or bracelet in case of loss of consciousness in an allergic reaction. Slide 32: Managing Food Allergy Education also includes high-risk situations involve eating out. This includes restaurants, movie theatres, other public dining areas, and a friend/relative s home. NutriSTEP (June 2010) 9

Module 5: Food Allergies and Intolerances Cross-contact is a serious risk which involves residual or trace amounts of an allergenic food that is unintentionally combined with other foods during preparation. Examples include harvesting, transportation, manufacturing, processing, storage, or serving. Nutritional adequacy is an important aspect to consider when one is allergic to various food items. The dietitian is uniquely qualified to ensure that nutritional needs are met while consuming a safe diet. Slide 33: Preventing/Delaying Allergic Disease An infant is considered high risk by the American Academy of Pediatrics if both parents, or one parent plus one sibling, have food allergies. There is still some debate regarding the degree to which breastfeeding prevents, reduces, delays, or increases the development of allergy. The CPS strongly recommends exclusive breastfeeding for the first 6 months of life for healthy, term infants. Breastfeeding may continue for up to two years and beyond. Although this recommendation is made for all babies and for many reasons, the AAP recognizes sufficient data to suggest a reduction in risk for food allergy in high risk infants. Slide 34: Preventing/Delaying Allergic Disease The American Academy of Pediatrics new Clinical Report states: Current evidence does not support: o dietary restrictions during pregnancy or lactation or o delaying introduction of allergen foods after 4-6 months of age to prevent atopic disease High risk infants may still benefit from nutritional intervention and delayed introduction of allergen foods Breastfeeding is still recommended exclusively for the first 6 months. o High risk infants may be fed hydrolyzed formula versus cow s milk formula to prevent/delay onset of food allergy There are positive effects on eczema from delayed introduction of solids; but evidence is conflicting. Slide 35: Allergen Labelling in Canada Health Canada is in the process of updating allergen labeling regulations. For example, when some ingredients such as flavours, flour, seasoning and margarine are used as ingredients in other foods they are not required to 10 NutriSTEP (June 2010)

A Preschool Nutrition Primer for Dietitians list the components of each of these foods. This can be a particularly serious problem for individuals on a gluten free diet who may unintentionally consume gluten from these unlabelled ingredients. The allergens that must be labeled on food products containing them as mandated by Health Canada are peanuts, tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts and walnuts), sesame seeds, milk, eggs, fish, crustaceans, shellfish, soy and wheat. After the update to the allergen labeling regulations, mustard will be added to this list. Onion and garlic were two allergens that Health Canada decided did not need to be included on food labels. There are also proposed exemptions for fining agents and coatings on prepackaged fresh fruits and vegetables containing allergens have been modified in the new allergen labeling regulations. Slide 36: Allergen Labelling in Canada Other amendments include: 1) Gluten sources declared when food contains gluten protein or modified gluten protein from barley, oats, rye, triticale or wheat, including kamut or spelt. 2) Sulphites declared when added directly to a food or when the total amount contained in the food is greater than 10 ppm. There are some food products still exempt from listing ingredients. However, if a manufacturer chooses to list ingredients on the label, they still need to follow allergen labeling regulations. Regional consultation workshops for the proposed amendments to the allergen labeling regulations took place in 2009 but comments were submitted online until February 10, 2010. The final regulations will be published sometime in the near future. Slide 37: This is the end of the presentation. There are practice questions that can be completed on your own time, and are not part of the audio presentation. The questions and correct answers are located in the separate link titled Modules 1-5: Case Study Questions and Answers. NutriSTEP (June 2010) 11

Module 5: Food Allergies and Intolerances Slides 38 and 39: No voice recording. 12 NutriSTEP (June 2010)