Adverse Reactions to FoodsProf. Dr. Saad Saleh Al AniSenior Pediatric ConsultantHead of Pediatric DepartmentKhorfakkan HospitalSharjah ,UAEsaadsalani@yahoo.com6/21/2013 1Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
Adverse reactions to foods consistof any untoward reactionfollowing the ingestion of a foodor food additive6/21/2013 2Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalDefinition
Facts•Like other atopic disorders, foodallergies have increased over the past 3decades primarily in “Westernized”countries•It now affect an estimated 3.5%of the U.S. population6/21/2013 3Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
Cont.Up to 6% of children experiencefood allergic reactions in the 1st3 yr of life, including about:-2.5% with cow’s milk allergy-1.5% with egg allergy-1% with peanut allergy6/21/2013 4Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
Cont.•Most children “outgrow” milk andegg allergies, with about 50% doingso within 3-5 yr.•In contrast, about 80-90% ofchildren with peanut, nut, orseafood allergy retain theirallergy for life6/21/2013 5Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
EtiologyAdverse Reactions to Foodsare classically divided into :1.Food intoleranceswhich are adverse physiologicresponses2.Food hypersensitivitieswhich include adverse immunologicresponses and allergies6/21/2013 6Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
Classification1.Food intolerancesa. Host Factors1.Enzyme deficiencies- Lactase (primary or secondary)- Fructase maturational delay)2.Gastrointestinal disorders- Inflammatory bowel disease- Irritable bowel syndrome6/21/2013 7Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
Cont.3.Idiosyncratic reactions-Caffeine in soft drinks (“hyperactivity”)4.Psychologic- Food phobias5.Migraines (rare)6/21/2013 8Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital
Cont.6/21/2013 9Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalb. Food Factors1.Infectious organisms- Escherichia coli- Staphylococcus aureus- Clostridium2.Toxins- Histamine (scombroid poisoning)- Saxitoxin (shellfish)
Cont.6/21/2013 10Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital-Caffeine- Theobromine (chocolate, tea)- Tryptamine (tomatoes)- Tyramine (cheese)3.Pharmacologic agents4.Contaminants-Heavy metals- Pesticides-Antibiotics
Cont.6/21/2013 11Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital2.Food hypersensitivitiesa. IgE-Mediated1.Cutaneous- Urticaria- Angioedema- Morbilliform rashes- Flushing- Contact urticaria2.Gastrointestinal- Oral allergy syndrome- Gastrointestinal anaphylaxis
Cont.6/21/2013 12Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital3. Respiratory-Acute rhinoconjunctivitis- Bronchospasm4. Generalized- Anaphylactic shock- Exercise induced anaphylaxis
Cont.6/21/2013 13Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalb. Mixed IgE- and Cell-Mediated1.Cutaneous- Atopic dermatitis- Contact dermatitis2.Gastrointestinal- Allergic eosinophilic esophagitisand gastroenteritis3. Respiratory- Asthma
Cont.6/21/2013 14Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalc. Cell Mediated1.Cutaneous- Contact dermatitis- Dermatitis herpetiformis2.Gastrointestinal- Food protein–induced:enterocolitis proctocolitis, and enteropathysyndromes-Celiac disease
Cont.6/21/2013 15Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital3. Respiratory- Food-induced pulmonary hemosiderosis(Heiner syndrome)d. Unclassified-Cow’s milk–induced anemia
6/21/2013 16Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalRememberIngestion of food normally leads tooral tolerance, which is the inductionof T-cell anergy and T regulatory cellsthat enable the systemic immunesystem to “ignore” the roughly 2% ofantigenic protein normally entering thesystemic circulation at each meal
Cont.6/21/2013 17Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalIn young infants, functional barriersand immunologic barriers areimmature, allowing increasedpenetration of food antigens, and thegut associated lymphoid tissue(GALT) appears less capable of“tolerizing” than the mature system
6/21/2013 18Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalPathogenesis•Food intolerances are the result of avariety of mechanisms, includinghost and food factors•Food hypersensitivities arepredominantly due to IgE mediatedand/or cell-mediated mechanisms
Cont.6/21/2013 19Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalwww.cincinnatichildrens.org
Cont.6/21/2013 20Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalwww.sciencedirect.com
Cont.6/21/2013 21Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalFood-specific IgE antibodiesBind to Fcε receptors on:Mast cellsBasophiles MacrophagesDendritic cellsMediators are releasedSmooth muscle contractionMucus secretionSymptoms of immediate hypersensitivityCertain allergensVasodilatation
Acute IgE-mediatedreactions6/21/2013 22Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalSymptoms elicited during acute IgE-mediatedreactions can affect the:•Skin (Urticaria, Angioedema, Flushing)•Gastrointestinal tract (Oral pruritus,Angioedema, Nausea, Abdominal pain,Vomiting, Diarrhea)
Cont.6/21/2013 23Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Respiratory tract (Nasal congestion,Rhinorrhea, Nasal pruritus, Sneezing ,Laryngeal edema, Dyspnea, Wheezing)•Cardiovascular system(Dysrhythmias, Hypotension, Lossof consciousness
Cont.6/21/2013 24Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•In the other major form of foodhypersensitivities lymphocytes, primarilyfood allergen– specific T cells, secreteexcessive amounts of various cytokinesthat lead to a “delayed,” more chronicinflammatory process affecting the:
Cont.6/21/2013 25Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Skin (pruritus , erythematous rash)•Gastrointestinal tract (cachexia, early satietyabdominal pain, vomiting, diarrhea),•Respiratory tract(food induced pulmonary hemosiderosis).
Mixed IgE andcellular responsesto food allergens6/21/2013 26Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalCan also lead to chronic disorderssuch as:- Atopic dermatitis- Asthma- Allergic eosinophilic gastroenteritis.
ClinicalManifestations6/21/2013 27Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•From a clinical and diagnosticstandpoint, it is most useful tosubdivide food hypersensitivitydisorders according to:- Predominant target organ- Immune mechanism
6/21/2013 28Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Gastrointestinal food allergies areoften the 1st form of allergyto affect infants and young childrenand typically manifest as:- Irritability- Vomiting or “spitting-up,”- Diarrhea- Poor weight gain.I. GastrointestinalManifestations
1.Food protein–inducedenterocolitissyndrome6/21/2013 29Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalTypically manifests as :• Irritability and protracted vomiting anddiarrhea →dehydration.• Vomiting generally occurs 1-3 hr afterfeeding• Continued exposure →:- Abdominal distention- Bloody diarrhea- Anemia- Failure to thrive
Cont.6/21/2013 30Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalSymptoms are most commonlyprovoked by:- Cow’s milk- Soy protein–based formulasA similar enterocolitis syndromeoccurs in older infants and childrenfrom:- Rice - Oat - Wheat- Nut - Peanut - Egg-Chicken - Turkey - Fishsensitivity.Hypotension occurs in about 15% ofcases after allergen ingestion
2.Food protein-inducedproctocolitis6/21/2013 31Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalPresents in the 1st few months of life asblood-streaked stools in otherwise healthyinfantsAbout 60% of cases occur amongbreast-fed infants, with the remainderlargely among infants fed cow’s milkor soy protein–based formulaBlood loss is typically modest butcan occasionally produce anemia
3.Food protein–inducedenteropathy6/21/2013 32Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Occasionally :Anemia, Edema, and Hypoproteinemiaoccur•Often manifests in the 1st several months of lifeas:- Diarrhea- Steatorrhea (not infrequent)- Poor weight gain•Symptoms include :- Protracted diarrhea- Vomiting ( up to 65% of cases)- Failure to thrive- Abdominal distention- Early satiety- Malabsorption
Cont.6/21/2013 33Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• Cow’s milk sensitivityis the most common cause of this food protein–induced enteropathy in young infants•Food protein–induced enteropathy hasalso been associated with sensitivity to- Soy - Chicken- Egg - Rice- Wheat - Fishin older children.
Celiac disease6/21/2013 34Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• The most severe form of protein-induced enteropathy•The full-blown form is characterized by:i. Extensive loss of absorptive villiii. Hyperplasia of the cryptsleading to:- Malabsorption - Chronic diarrhea- Steatorrhea - Abdominal distention- Flatulence-Weight loss or failure to thrive•Occurs in 1 : 100-1 : 250 of the U.S. population,although it may be “silent” in many patients
Cont.6/21/2013 35Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Genetically susceptible individuals(HLA-DQ2 or DQ8) demonstrate acell-mediated response to tissuetransglutaminase (tTGase) deamidatedgliadin, which is found in:- Wheat - Rye – Barley•Oral ulcers and other extraintestinal symptomssecondary to malabsorption are not uncommon.
4.Allergiceosinophilicesophagitis6/21/2013 36Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Of children <1 yr of age presenting withGER, 40% have cow’s milk–induced reflux•May appear from infancy through adolescence,more frequently in boys.•In young children , it is primarily cell mediatedand manifests as:- Chronic gastroesophageal reflux (GER)- Intermittent emesis - Food refusal- Abdominal pain - Dysphagia– Irritability - Sleep disturbance-Failure to respond to conventional refluxmedications
5.Allergiceosinophilicgastroenteritis6/21/2013 37Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Occurs at any age and causes symptoms similar tothose of esophagitis as well as prominent weight lossor failure to thrive, both of which are the hallmarksof this disorder.•More than 50% of patients with thisdisorder are atopic, and food-inducedIgE-mediated reactions have beenimplicated in a minority of patients.
Cont.6/21/2013 38Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• Generalized edema secondary tohypoalbuminemia may occur in someinfants with marked protein- losingenteropathy.
6.Oral allergysyndrome (pollen-food syndrome)6/21/2013 39Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Is an IgE mediated hypersensitivity that occurs in manyolder children with birch pollen– and ragweed-inducedallergic rhinitis.•Symptoms are usually confined to the oropharynxand consist of the rapid onset of :- Oral pruritus- Tingling and angioedema of the lips, tongue,palate, and throat- Occasionally :* Sensation of pruritus in the ears* Tightness in the throat
Cont.6/21/2013 40Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• Symptoms are generally short lived and arecaused by local mast cell activation by freshfruit and vegetable proteins that crossreact with:- Birch pollen( Apple , Carrot, Potato, Celery,Hazel nuts, Kiwi)- Ragweed pollen(Banana, Melons such as watermelonand Cantaloupe)
7.Acutegastrointestinalallergy6/21/2013 41Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalGenerally manifests as:- Acute abdominal pain- Vomitingthat accompany IgE-mediated allergicsymptoms in other target organs.
II. SkinManifestations6/21/2013 42Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalCutaneous food allergies are alsocommon in infants and young children.
1.Atopic dermatitis6/21/2013 43Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•The younger the child and the moresevere the eczema, the more likelyfood allergy is playing a pathogenicrole in the disorder.•Is a form of eczema that generally begins inearly infancy and is characterized by :- Pruritus- Chronically relapsing course- Association with asthma and allergic rhinitis•30% of children with moderate to severeatopic dermatitis have food allergies
2.Acuteurticaria andangioedema6/21/2013 44Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Are among the most common symptoms of foodallergic reactions•The onset of symptoms may be veryrapid, within minutes after ingestion ofthe responsible allergen•Symptoms result from activation ofIgE bearing mast cells by circulatingfood allergens that are absorbedand circulated rapidly throughoutthe body
Cont.6/21/2013 45Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Chronic urticaria and angioedemaare rarely due to food allergies.•Foods most commonly incriminated in childreninclude :-Egg - Milk - Peanuts - Nuts•Reactions to various seeds (Sesame, Poppy)and fruits (Kiwi)are becoming more common.
III. RespiratoryManifestations6/21/2013 46Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• Many studies show that nasal congestionin infants is rarely caused by milk allergy•Respiratory food allergies are uncommonas isolated symptoms.
1.Food-inducedrhinoconjunctivitis6/21/2013 47Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Wheezing occurs in about 25% of IgE-mediated food allergic reactions, butonly about 10% of asthmatic patientshave food-induced respiratorysymptoms.•Symptoms typically accompany allergic symptomsin other target organs, such as skin, and consist oftypical allergic rhinitis symptoms :-Periocular pruritus and tearing- Nasal congestion and pruritus- Sneezing- Rhinorrhea .
IV. Anaphylaxis6/21/2013 48Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Food allergic reactions are the single most commoncause of anaphylaxis seen in hospital emergencydepartments•In addition to the rapid onset of cutaneous,respiratory, and gastrointestinal symptoms,patients may demonstrate cardiovascularsymptoms, including :-hypotension- vascular collapse- cardiac dysrhythmiaswhich are presumably caused bymassive mast cell– mediator release.
Diagnosis6/21/2013 49Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• Thorough medical history whether apatient’s symptomatology represents:- An adverse reaction- The adverse food reaction is:* Intolerance* Hypersensitivity reactionand whether it is likely to be:i. IgE-mediatedii. Cell-mediatedresponse
Cont.6/21/2013 50Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalThe following facts should be established:(1) The food suspected of provoking the reaction and thequantity ingested,(2) The interval between ingestion and the developmentof symptoms,(3) The types of symptoms elicited by the ingestion(4) Whether ingesting the suspected foodproduced similar symptoms on other occasions(5) Whether other inciting factors, such asexercise, are necessary,(6) The interval from the last reaction to thefood
Cont.6/21/2013 51Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Prick skin tests and in vitro laboratorytests are useful for demonstrating IgEsensitization•Many fruits and vegetables require testingwith fresh produce because labileproteins are destroyed duringcommercial preparation
Cont.6/21/2013 52Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•A negative skin test result virtually excludesan IgE-mediated form of food allergy•Majority of children with positive skintest responses to a food do not reactwhen the food is ingested, so moredefinitive tests, such as quantitativeIgE tests or food elimination andchallenge, are often necessary toestablish a diagnosis of foodallergy
6/21/2013 53Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Serum food-specific IgE levels≥15 kUA/L for milk(≥5 kUA /L for children ≤1 yr)≥7 kUA /L for egg(≥2 kUA /L for children <3 yr)≥14 kUA /L for peanutAre associated with a >95%likelihood of clinical reactivity tothese foods in children withsuspected reactivityCont.
6/21/2013 54Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• There are no laboratory studies tohelp identify foods responsible forcell-mediated reactions.•Elimination diets followed byfood challenges are the onlyway to establish the diagnosisCont.
6/21/2013 55Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital• Before a food challenge is initiated,the suspected food should be eliminatedfrom the diet for:- 10-14 daysfor IgE-mediated food allergy- up to 8 wkfor some cell mediated disorders,such as allergic eosinophilicesophagitis.Cont.
Treatment6/21/2013 56Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Complete elimination of commonfoods (milk, egg, soy, wheat, rice,chicken, fish, peanut, nuts) is verydifficult because of their widespreaduse in a variety of processedfoods.•Appropriate identification andelimination of foods responsible for foodhypersensitivity reactions are the onlyvalidated treatments for food allergies
6/21/2013 57Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Children with:- Asthma and IgE-mediated food allergy- Peanut or nut allergy- History of a previous severe reactionshould be given:* Self- injectable epinephrine (EpiPen)* Written emergency plan in caseof accidental ingestionCont.
6/21/2013 58Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospitalCont.• Many food allergies are outgrown• Reevaluation periodically is essential• Other forms of therapy:-Anti-IgE immunoglobulin therapy-Engineered recombinant foodprotein vaccines-Herbal formulations.•Tolerance may be generated byheating (cooking) the food (milk)
Prevention6/21/2013 59Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital•Exclusive breast-feeding•Hydrolyzed milk-based formulasfor the first 4-6 months of life mayreduce allergic disorders
References6/21/2013 60Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital1. http://www.foodallergy.org2. Angier E, Sheikh A: Pollen food syndrome in a teenagestudent. BMJ 2010; 340:b34053. Boyce JA, Assaad A, Burks AW, et al: Guideline for the diagnosis andmanagement of food allergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol 2010; 126(6):S1-S584. Lack G: Epidemiological risk factors for food allergy. J Allergy ClinImmunol 2008; 121:1331-13365. Pratt CA, Demain JG, Rathkopg MM: Food allergy and eosinophilicgastrointestinal disorders: guiding our diagnosis and treatment. Curr ProbPediatr Adolesc Health Care 2008; 38:165-196.6. Sackeyflo A, Senthinathan A, Kandaswamy P, et al: Diagnosis and assessmentof food allergy in children and young people: summary of NICEguidance. BMJ 2011; 342:544-5467. http://www.expertconsultbook.com?
6/21/2013 61Adverse reactions to foods Prof. Dr. Saad S Al Ani KhorfakkanHospital