The Nuts and Bolts of Food Allergy Andrew Bagg, M.D.

PRESIDENT FAAISASSISTANT PROFESSOR

U.C.F. COLLEGE of MEDICINEAllergy Asthma Specialists, P.A.

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NO COMMERCIAL SUPPORT WAS PROVIDED FOR THIS ACTIVITY.

Food Reactions

• An adverse food reaction is a general term for any untoward response to the ingestion of a food.

• Adverse food reactions can be divided into food allergies, which are immunologically mediated, and all other reactions, which are nonimmunologic.

• Adverse food reactions are common and often assumed by patients to be allergic in nature.

• However, nonimmunologic reactions are more common than true food allergies.

Types of reactions

• IgE mediated allergy (anaphylaxis, hives)• Delayed allergy (atopic dermatitis)• Mixed type (eosinophilic esophagitis)• Intolerance (example lactose)• Food induced Colitis (FPIES)

IgE-mediated

• IgE-mediated food allergic reactions are rapid in onset, typically beginning within minutes to two hours from the time of ingestion

Urticaria and Angioedema

• Most common cutaneous manifestations of food hypersensitivity reactions, generally appearing within minutes of ingestion

• Food allergy ~20% of cases of acute urticaria

Contact Urticaria

• Hives only on skin that was in direct contact with the food.

• In addition to the common allergens, raw meats, seafood, raw vegetables and fruits, mustard, rice, and beer

Oral allergy syndromePollen-food allergy syndrome: (OAS)• A form of contact allergy common in patients with allergic rhinitis to

pollen• Heat-labile proteins (eg, profilins) cross reactive with pollen proteins. • Symptoms –oropharynx : pruritus, mild swelling of the lips, tongue,

palate, and throat upon ingestion of fresh, uncooked fruits and vegetables [1].

• Symptoms usually subside within minutes, However, progression to systemic symptoms can occur and anaphylaxis has been reported [2].

• Symptoms may be more noticeable during the associated pollen season.

• 1.Bock SA, Atkins FM. Patterns of food hypersensitivity during sixteen years of double-blind, placebo-controlled foodchallenges. J Pediatr 1990; 117:561.

• 2.Bruijnzeel-Koomen C, Ortolani C, Aas K, et al. Adverse reactions to food. European Academy of Allergology and Clinical Immunology Subcommittee. Allergy 1995; 50:623.

Respiratory Tract Symptoms

• Asthma and environmental allergies are more common in children with food allergy. Nasal, and lower respiratory tract symptoms are common components of systemic food allergic reactions (anaphylaxis).

• Isolated allergic rhinoconjunctivitis or asthma in response to foods is rare.

Gastrointestinal Symptoms

• Nausea, abdominal pain, abdominal cramping, vomiting, and/or diarrhea, are more prominent features in anaphylaxis due to ingestion of a food allergen.

• The term gastrointestinal anaphylaxis is used when GI symptoms occur in isolation.

• However, GI symptoms are rarely the sole manifestations of a food-allergic reaction.

• The onset of upper gastrointestinal symptoms (nausea, vomiting, abdominal pain) is generally minutes to two hours after ingestion of the offending food, but lower gastrointestinal symptoms, such as diarrhea, can begin two to six hours after ingestion.

• 1. Sampson HA. Adverse reactions to foods. In: Middleton's allergy: Principles and practice, 6th ed, Adkinson NF, Yunginger JW, Busse WW, et al (Eds), Mosby, St. Louis, MO 2003. p.1619.

Triggers of Anaphylaxis: Food• Although nearly any food is capable of causing an allergic reaction,

only eight foods account for 90 percent of all food-allergic reactions in the United States:

• Peanut• Tree nuts• Milk • Egg • Wheat • Soy• Fish• Shellfish

Less Common Food Triggers

• CornGelatinMeat (beef, chicken, mutton, and pork)Seeds (sesame, sunflower, and poppy being the most common)Spices (caraway, coriander, garlic, mustard, etc.)

Most Frequent Signs and Symptoms of Anaphylaxis

Manifestation Percent

Urticaria/angioedema 88

Upper airway edema 56

Dyspnea/wheeze 47

Flush 46

Hypotension 10-33

Gastrointestinal 30

Oral: pruritus of lips, tongue, and palate; edema of lips and

tongue; metallic taste in mouth

Cutaneous: flushing, pruritus, urticaria, angioedema,

morbilliform rash, and pilor erecti; pruritus in unusual

places (scrotum, vagina, ear)

Symptoms/Signs of Anaphylaxis

Gastrointestinal: nausea, abdominal pain (colicky), vomiting

(large amount of “stringy” mucus), diarrhea

Cardiovascular: feeling of faintness, syncope, chest pain,

dysrhythmia, hypotension

Symptoms/Signs of Anaphylaxis

Respiratory

• Nose: pruritus, congestion, rhinorrhea, and sneezing

• Laryngeal: pruritus and “tightness” in the throat,

dysphagia, dysphonia and hoarseness/stridor, dry

“staccato” cough

• Lungs: shortness of breath, dyspnea, chest tightness,

cough, and wheezing

Symptoms/Signs of Anaphylaxis

Other: periorbital pruritus, erythema, and edema;

conjunctival erythema and tearing; aura of impending

“doom,” seizures; lower back pain and uterine

contractions in women

Symptoms/Signs of Anaphylaxis

Food-dependent exercise-induced anaphylaxis

• Anaphylaxis that occurs only if the patient exercises or exerts themselves within two to four hours of ingestion of food

• Wheat, celery, and seafood

NON IgE-MEDIATED REACTIONS

• Food protein-induced enterocolitis syndrome (entire gastrointestinal tract) (FPIES)

• Food protein-induced enteropathy (small bowel)

• Food protein-induced proctitis and proctocolitis (rectum and colon)

• Celiac disease and dermatitis herpetiformis• Food-induced pulmonary hemosiderosis

(Heiner's syndrome)

FPIES

• Passage of blood-tinged stools and mucus in breastfed infant

• Between two and eight weeks of age and resolves in a few days with complete elimination of the offending protein.

• Cow’s milk from mother’s diet

FPIES

• Vomiting and diarrhea, bloody stools.• Main trigger is milk and soy

Celiac Disease• Chronic diarrhea, anorexia, abdominal

distension and pain, failure to thrive or weight loss, and sometimes also vomiting

• Treatment is avoidance of gluten

Foods That Contain Gluten

Nonimmunologic Food Reactions

• Far more common than food allergy. Examples include :• Lactose intolerance, • Gastroesophageal reflux, • Disorders resulting from anatomic and neurologic

abnormalities, • Enzymatic deficiencies and metabolic diseases, • Toxins and gastrointestinal infections, • Food additives,• Food chemicals triggering migraine headaches• Bruijnzeel-Koomen C, Ortolani C, Aas K, et al. Adverse reactions to food. European Academy of Allergology and Clinical

Immunology Subcommittee. Allergy 1995; 50:623.

MIXED IgE AND NON IgE-MEDIATED REACTIONS

Atopic Dermatitis

Atopic Dermatitis

• Food allergies may exacerbate atopic dermatitis, • The flare occurs within minutes to a few hours if the

reaction is IgE-mediated• Hours to days if the reaction is non IgE-mediated. • The patient has persistent lesions if the food is eaten

chronically.

Eosinophilic Esophagitis (EoE)

Infants present with feeding disorders• Older children /adults: dysphagia, vomiting, and abdominal pain. • Food impaction in adolescents/ adults. • Cow's milk, egg, soy, corn, wheat, and beef• Elimination or elemental diets result in clinical and

histologic improvement in most.

Diagnostic Testing For Food Allergy

• Skin Testing• (prick test)• More accurate when

negative, lower cost, immediate results

• Specific IgE Lab• Less sensitive and more

expensive

• IgG food lab not useful• Both tests false + and -

Oral Food Challenges (OFC’s)

• The gold standard for diagnosis• OFCs may also be used to determine if a food

allergy has resolved. In addition, they can be undertaken to define other adverse reactions to foods, such as intolerance.

Food Protocol Example• RUB FOOD AROUND LIPS ONLY. MONITOR 20 MINUTES THEN IF NO SYMPTOMS,• SWALLOW FOOD EQUIVALENT TO THE TOP OF A PENCIL ERASER OR 1/8 TEASPOON. • MONITOR 20 MIN AND DOUBLE THE AMOUNT OF FOOD EVERY 20 MINUTES WATCHING FOR

ADVERSE REACTION UNTIL THE PATIENT HAS TAKEN ENOUGH FOOD THAT IS EQUIVALENT TO 2-3 TEASPOON.

• MONITOR FOR ADDITIONAL 60 MIN.

FOOD AMOUNT or mg TIME

VITAL SIGNSPULSE: BP: RR: REACTION

Peanut Rub lips (optional)

1/8 tsp

¼ tsp

½ tsp

1 tsp

2 tsp

Rest of serving

Post-challenge counseling

• Some patients and parents may continue to be fearful about eating the food, despite a negative challenge , and this can result in continued avoidance .

• Avoidance or infrequent exposure may result in resensitization to the allergen.

• A repeat challenge may be required in patients who have continued to avoid the food.

• Flammarion S, Santos C, Romero D, et al. Changes in diet and life of children with food allergies after a negative food challenge. Allergy 2010; 65:797.

Treatment

• Avoidance• Injectable epinephrine (epi-pen, auvi-Q,

generic twinject)• and diphenhydramine (benadryl)

Tips for Avoiding Food Allergens• Read ingredient labels thoroughly, and at least twice.• Check packaging thoroughly • Avoid products with advisory labels for your specific allergen. • Read ingredient statements for non-food products, such as lotions, soaps,

hair care products, and medications.• Speak to a restaurant’s manager and chef about the accommodations you

need before dining out. • Before traveling, plan for how food allergies will be managed. For example:

Pack food for the trip? Have food shipped? Additional medication?• Teach the child which foods are to be avoided and what these foods look like.

Role-play with the child so they know how to respond if a well-meaning person offers food or drink.

• Eliminate or reduce exposure to an allergen while still allowing the child to equally participate in an activity alongside peers/classmates.

• Be sure all those caring for or teaching the child are aware of the food allergy action plan and when/how to use medication to treat symptoms.

• http://www.foodallergy.org/

Be Prepared…Be Safe

An effective food allergy treatment plan includes all of the following:

• Strict avoidance of problem foods• Working with the doctor to develop a

Food Allergy & Anaphylaxis Emergency Care Plan• Wearing emergency medical identification (e.g., bracelet,

other jewelry) at all times• Carrying medication everywhere• Medication at the first sign of a reaction• Getting to an emergency room for follow-up treatment for

a severe reaction

Anaphylaxis in the School

SettingGuidelines

www.faais.org

References

• NIAID-Sponsored Expert Panel, Boyce JA, Assa'ad A, et al. Guidelines for the diagnosis and management of foodallergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol 2010; 126:S1.

Skin testing for environmental allergens such as: pollen, dust, mold, dog and cat dander, as well as food allergySpecific blood test for allergies (if appropriate and needed)Blood tests for patients with recurrent infections (evaluate the immune system)Food allergy evaluations and oral food challenge testingDrug allergy evaluations, testing & challengePatch testing for identification of rashes (for contact allergy)Skin biopsyRhinoscopy to examine the nasal passages and throatTympanogram testing of the eardrumPulmonary function testing (breathing capacity test)Methacholine challenge for asthma diagnosisExercise challenge testing to evaluate exercise-induced asthmaAll forms of Allergen Immunotherapy

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