![Criteria for Anaphylaxis
(anaphylaxis is likely)
1. Acute onset of an illness (minutes to
several hours) with involvement of the skin
and/or mucosal tissue (e.g., generalized
hives, pruritus or flushing, swollen
lips/tongue/uvula)
AND AT LEAST ONE OF THE FOLLOWING
a. Respiratory compromise (e.g., dyspnea,
wheeze/bronchospasm, stridor, reduced peak expiratory flow
(PEF), hypoxemia)
b. Reduced blood pressure (BP) or associated symptoms of end-
organ dysfunction (e.g.,hypotonia [collapse], syncope,
incontinence)
NIH Panel report 2006](https://image.slidesharecdn.com/foodallergyfornonallergens-241111075022-e0b4152b/85/Module-on-Food-Allergy-for-non-allergists-ppt-12-320.jpg)
![Criteria for Anaphylaxis
(anaphylaxis is likely)
OR
2. Two or more of the following that occur
rapidly after exposure to a likely allergen for
that patient (minutes to several hours):
a. Involvement of the skin/mucosal tissue (e.g., generalized
hives, itch/flush, swollen lips/tongue/uvula)
b. Respiratory compromise (e.g., dyspnea,
wheeze/bronchospasm, stridor, reduced PEF, hypoxemia)
c. Reduced BP or associated symptoms (e.g., hypotonia
[collapse], syncope, incontinence)
d. Persistent GI symptoms (e.g., crampy abdominal pain,
vomiting)](https://image.slidesharecdn.com/foodallergyfornonallergens-241111075022-e0b4152b/85/Module-on-Food-Allergy-for-non-allergists-ppt-13-320.jpg)
![Criteria for Anaphylaxis
(anaphylaxis is likely)
OR
3. Reduced blood pressure following
exposure to known allergen for that patient
(minutes to several hours):
a. Infants and Children: low systolic BP (age-specific) or >30%
drop in systolic BP*
b. Adults: systolic BP <90 mmHg or >30% drop from that
person’s baseline
* Low systolic BP for children is defined as <70 mmHg from 1
month to 1 year; less than (70 mmHg + [2 x age]) from 1-10
years; and <90 mmHg from age 11-17 years.](https://image.slidesharecdn.com/foodallergyfornonallergens-241111075022-e0b4152b/85/Module-on-Food-Allergy-for-non-allergists-ppt-14-320.jpg)
Module on Food Allergy for non-allergists .ppt
- 1. Food Allergy: A Teaching Module For The Non-Allergist (Draft Presentation) Multi-Faceted Food Allergy Education Program Funding provided by the United States Department of Agriculture
- 2. Learning Objectives • Understand the clinical manifestations of food allergic disorders • Appreciate the utility of tests used to diagnose food allergy • Recognize and understand the management of food-induced anaphylaxis • Appreciate and respond to the educational needs of patients diagnosed with food allergy in regard to avoidance and treatment
- 3. Perceived versus True Food Allergy • About 20% in the general population perceive themselves to have a “food allergy” • Food allergy is an adverse immune response to food protein – IgE antibody mediated: sudden allergic reactions – Cell-mediated reactions: chronic symptoms • Many reasons for adverse reactions to foods – Intolerance (e.g., lactose intolerance) – Toxic (e.g., food poisoning) – Pharmacologic (e.g., caffeine) • Estimated prevalence of food allergy (increasing) – 6-8% of young children – 2-4% of adults
- 4. Life-Threatening Food Allergies Are Associated with Production of IgE Antibodies • IgE antibodies circulate in the bloodstream and bind to receptors on basophils and tissue mast cells • Binding of a food protein to the antibodies triggers release of mediators (e.g., histamine) causing symptoms – Basis for allergy tests (serum tests for food- specific IgE and allergy prick/puncture skin tests) Mast cell IgE antibody Histamine Food Protein Release of Histamine Armed Mast Cell Activated Mast Cell
- 5. Common Causal Foods • Common for severe reactions – Peanut – Tree Nuts (e.g., walnut, cashew) – Shellfish (e.g., shrimp) – Fish (e.g., cod) – But, potentially others such as seeds, etc. • Common foods causing mild reactions (usually) – Fruits – Vegetables • Common allergens for children, usually outgrown* – Milk – Egg – Wheat – Soy *20% of young children “outgrow” a peanut allergy By school-age
- 6. IgE-Mediated Cell-mediated (Non-IgE-Mediated) Skin Urticaria Atopic Dermatitis Angioedema Dermatitis herpetiformis (papulovesicular rash) Respiratory Asthma Rhinitis Gastrointestinal GI “Anaphylaxis” Eosinophilic Celiac disease Oral Allergy gastrointestinal Infant syndrome disorders gastrointestinal Systemic disorders Anaphylaxis Food-associated, exercise-induced anaphylaxis Spectrum of Food Allergy
- 7. Diagnosis May Be a Challenging • Chronic symptoms – Gastrointestinal, skin or respiratory – Only sometimes related to food allergy – No history of a “trigger” food • Multiple possible triggers – Many foods in the diet • Definitive outcomes needed – To know what to eat/avoid • Masqueraders – Many illnesses can appear to be food allergy • “Imperfect” tests – Detection of IgE to a food (e.g., by serum or skin tests) reveals “sensitization” which is not always a proof of clinical reaction – Approximate sensitivity is 50-80%, specificity 90-95% (false positives and false negatives) Eosinophilic esophagitis Atopic dermatitis Neurologically-mediated vasodilatation) caused by tart foods (auriculotemporal syndrome) Positive skin test
- 8. Food Allergy Evaluation* • History – Details of diet, possible triggers, alternative diagnoses • Physical – To exclude other causes • Testing – Tests for IgE to suspected trigger(s) • Skin prick tests by an allergist • Serum tests widely available (not affected by anti- histamines) – May require diet elimination/physician supervised oral food challenges *Additional procedures may be needed
- 9. Tests for Food-Specific IgE • Amount of food-specific IgE reflected by serum level or skin test size • Increasing “level” roughly reflects increasing risk of a reaction • “Level” does not correlate well with “severity” • Modest sensitivity and specificity – makes tests poor for “screening” – clinical history is very important – reaction could occur despite “negative” test
- 10. Food Anaphylaxis • Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death • Food is the most common cause of community anaphylaxis • Anaphylaxis may be biphasic – Quiescent period after initial symptoms and recurrence of symptoms in the subsequent hours
- 11. Food Anaphylaxis • Risk factors for fatal, food-induced anaphylaxis – Major risk factor: delayed use of epinephrine – High risk groups: teenagers/young adults – High risk co-morbidity: asthma – Confusing physical symptom: urticaria may be absent
- 12. Criteria for Anaphylaxis (anaphylaxis is likely) 1. Acute onset of an illness (minutes to several hours) with involvement of the skin and/or mucosal tissue (e.g., generalized hives, pruritus or flushing, swollen lips/tongue/uvula) AND AT LEAST ONE OF THE FOLLOWING a. Respiratory compromise (e.g., dyspnea, wheeze/bronchospasm, stridor, reduced peak expiratory flow (PEF), hypoxemia) b. Reduced blood pressure (BP) or associated symptoms of end- organ dysfunction (e.g.,hypotonia [collapse], syncope, incontinence) NIH Panel report 2006
- 13. Criteria for Anaphylaxis (anaphylaxis is likely) OR 2. Two or more of the following that occur rapidly after exposure to a likely allergen for that patient (minutes to several hours): a. Involvement of the skin/mucosal tissue (e.g., generalized hives, itch/flush, swollen lips/tongue/uvula) b. Respiratory compromise (e.g., dyspnea, wheeze/bronchospasm, stridor, reduced PEF, hypoxemia) c. Reduced BP or associated symptoms (e.g., hypotonia [collapse], syncope, incontinence) d. Persistent GI symptoms (e.g., crampy abdominal pain, vomiting)
- 14. Criteria for Anaphylaxis (anaphylaxis is likely) OR 3. Reduced blood pressure following exposure to known allergen for that patient (minutes to several hours): a. Infants and Children: low systolic BP (age-specific) or >30% drop in systolic BP* b. Adults: systolic BP <90 mmHg or >30% drop from that person’s baseline * Low systolic BP for children is defined as <70 mmHg from 1 month to 1 year; less than (70 mmHg + [2 x age]) from 1-10 years; and <90 mmHg from age 11-17 years.
- 15. Treatment of Anaphylaxis: Epinephrine • Dose: 0.01 mg/kg (max 0.5 mg) – 0.01 cc/kg of 1:1,000 concentration • Route: intramuscular – Higher and quicker peak serum levels compared to subcutaneous – Consider intravenous for severe hypotension/arrest • Monitor, titrate, higher risk of dysrhythmias • Location: anterior, lateral thigh (vastus lateralis) – Higher and quicker peak serum levels compared to deltoid • Frequency: ~5-15 minutes (adjusted clinically)
- 16. Treatment of Anaphylaxis: Typical Treatments • Antihistamine (H1 and H2 Blockers) – Slower in onset than epinephrine (e.g. 30 minutes) – Second-line therapy – Little effect on blood pressure – Helpful for urticaria, angioedema, pruritus – Addition of H2 blockade (may improve treatment of cutaneous manifestations) • Adrenergic agents – Inhaled beta-2 agonists may be useful for bronchospasm refractory to epinephrine • Corticosteroids – May prevent protracted/biphasic course but not proven
- 17. Treatment of Anaphylaxis: Advanced Treatment Options • Oxygen • Fluid resuscitation • Vasopressors • Glucagon – Presumptive for epinephrine recalcitrant/beta- blockade • Physical position during anaphylactic shock (unless precluded by vomiting or respiratory distress) – Recumbent with legs raised – Case reports of death when raised to upright position (“empty ventricle”)
- 18. Observation Following Anaphylaxis: ≥ 4 hours • Symptoms may recur ( studies vary, 1- 20% of episodes) • Biphasic reaction may be more severe • Onset varies (studies vary, 1-72 hours) • Recommended observation 4-6 hours for most patients – Longer for more severe symptoms – More caution for patients with asthma
- 19. Aftercare/Food Allergy Care • Avoidance/dietary elimination – At home/Manufactured products – Restaurants/vacation/travel – School – Unexpected exposures • Treatment of a reaction – Emergency plans – Self-administered epinephrine – Medical identification jewelry
- 20. Dietary Elimination • Hidden ingredients (peanut in sauces or egg rolls) – Must educate patients to ask questions in restaurants • Labeling issues (changes, errors) – Must educate patient to read label each time • Cross contamination (shared equipment) • Seeking assistance – Registered dietitian: (www.eatright.org) – Food Allergy & Anaphylaxis Network: (www.foodallergy.org; 800-929-4040) – Center for Food Safety and Applied Nutrition: (www.csfan.fda.gov)
- 21. Food Allergen Labeling and Consumer Protection Act (Effective Jan 2006) • What the law addresses: – Must disclose “major food allergens” in plain English words • Major food allergens: milk, egg, wheat, soy, peanut, tree nuts, fish, Crustacean shellfish – Must name specific tree nut, fish or shellfish (e.g. cashew, tuna, shrimp) – May list scientific name (e.g. casein) but if English word equivalent also used (e.g. milk)
- 22. Food Allergen Labeling and Consumer Protection Act (Effective Jan 2006) • What the law does not address: – Allergens not considered “major” (i.e. sesame or garlic) may not be identified • May be hidden using terms such as “spices” or “natural flavor” – Does not apply to non-crustacean shellfish (i.e. clam, squid) – “May contain” provisional labeling is voluntary
- 23. Restaurants • Indicate ALLERGY to staff – Could otherwise mistake for food “preference” • Careful line of communication for food preparation • Avoid buffet, sauces, high risk restaurants (e.g., Asian restaurant with peanut allergy/ seafood restaurant with seafood allergy) • Avoid cross-contact with allergens • Consider “Chef Cards” From: www.foodallergy.org
- 24. Strategies for Food Allergy in School: Avoidance • Increased supervision during meals, snacks • No sharing (food, containers, utensils) • Clean tables, toys, hands (younger children) • Substitutions: meals, cooking, crafts, science • Ingredient labels for foods brought in • Education of staff • Don’t miss the bus: no food parties, ensure communication/supervision
- 25. Strategies for Anaphylaxis in School: Treatment • Physician-directed protocols • Review of protocols, assignment of roles • Medications readily available (not locked) • Education and review: – signs of reaction – technique of medication administration – basic first aid – notification of emergency medical system (911)
- 26. Resources • The Food Allergy & Anaphylaxis Network • www.foodallergy.org • 800-929-4040
- 27. Recommendations for School Available at :www.foodallergy.org
- 28. Unusual/Casual Exposures • Kissing (passionate) • Cosmetics • Medications/vaccines (read labels/inserts) • Airborne (usually when cooking resulting in fumes from food, such as eggs, seafood, milk)
- 29. Prescription of Self-Injectable Epinephrine • Indication – Definite: For previous anaphylaxis – Other: Perceived high risk • Examples: peanut/nut/seafood allergy and asthma, reaction to trace amounts, remote locations • Dose of self-injectable epinephrine – Available as 0.15 mg (package insert 33-66 lbs) – Available as 0.30 mg (package insert > 66 lbs) – Physician discretion (e.g., switch to 0.3 mg at 55 lbs to avoid under-dosing) – Prescription of 2 doses
- 30. Treatment Plan: Use of Self- Injectable Epinephrine • Training on self-injector use – Errors in activating are common, must review – Trainers available (www.epipen.com;www.twinject.com) – DVDs, tapes and websites with instructions from manufacturers • Training on when to inject – For anaphylaxis as defined earlier – Consider for fewer symptoms depending upon history/circumstances • Examples: previous severe anaphylaxis and current certain ingestion despite no symptoms, mild symptoms but remote to medical care • Seek advanced care – Activate emergency services (e.g., 911)
- 31. Emergency Action Plan/Identification Jewelry From www.foodallergy.org www.medicalert.org
- 32. Epinephrine Device Demonstration Epipen Twinject Click on the device above for which you would like to view a video demonstration
- 33. Allergy Referral • Persons on limited diet for perceived adverse reactions • Persons with diagnosed food allergy • Persons with allergic symptoms in association with food exposures The American Academy of Allergy, Asthma and Immunology: www.aaaai.org The American College of Allergy, Asthma and Immunology: www.acaai.org
- 34. EXAMPLES
- 35. Sarah • Age 37 • Ate a cashew cookie and developed anaphylaxis treated in the emergency department • History indicates she typically tolerates cashews, walnuts, almond, peanut, pecan, pistachio • Which is the most appropriate course of action? A) Advise to avoid all tree nuts B) Advise to avoid cashew C) Perform allergy tests to cashew D) Determine the ingredients of the cookie
- 36. Diagnosis Requires Careful History • The cookie package indicated that Brazil nuts were an ingredient • Sarah had been eating cashews but never frequently ate Brazil nuts • Allergy tests were positive to Brazil nut and negative to cashew • Instructions could include avoidance of all nut products (may have Brazil) or to continue ingestion of tolerated nuts when certain that Brazil nut is not included
- 37. Ronald • 35 year old with peanut allergy • Ate a cookie and has a few hives around the mouth, no other symptoms • Which of the following actions is most appropriate? A) Inject epinephrine now B) Inject epinephrine if symptoms progress
- 38. The Answer Could Depend Upon The Clinical History • HISTORY #1 • Has had 6 lifetime accidental peanut ingestions • All reactions resulted in hives • No history of asthma • Could monitor and inject if progresses/inject if uncertain • HISTORY #2 • 6 lifetime peanut ingestions – 5 with breathing difficulty – 2 required respirator support/ionotropes – 5 required epinephrine – One resulted in hives and vomiting • Should inject epinephrine
- 39. Jim • 3 year old • Soy allergic • Eating hot dog at school picnic (“all beef”) • Teacher sees he is thrashing around • Not breathing, turning blue • Teacher has his Self-injectable with her • What should she do?
- 40. Masquerader of Anaphylaxis • Choking • Panic attack • Myocardial infarction • Must assess history – Jim was likely choking-Heimlich maneuver – May err on side of administering epinephrine if not certain
- 41. Stephanie • 16 years old, has asthma • Sesame allergy (known) • Ate a bagel with no visible sesame • Has no hives, develops repetitive coughing, hoarse throat, trouble swallowing • What treatment is most appropriate? A) Antihistamine B) Injected epinephrine C) Asthma inhaler D) Heimlich maneuver
- 42. Anaphylaxis May Occur Without Hives • Inject Epinephrine
- 43. Billy • 3 years old, asthma • Ate friend’s snack • Within minutes: Hives, wheezing • IN ER: given epinephrine, antihistamine • In ER 45 minutes after ingestion, no more symptoms • Discharged home by ER What suggestions might you have before he leaves the ER?
- 44. Follow-Up Care For Food Anaphylaxis • Query for possible trigger/suggest avoidance • Refer for/perform diagnostic testing • Prescribe/teach self-injectable epinephrine/emergency plan • Monitor additional time (4-6 hours) to ensure no biphasic/protracted reaction
- 45. Food Allergy and Anaphylaxis Summary • Diagnosis requires careful history, testing – consider allergy referral • Instruct patients on the signs of an allergic reaction/anaphylaxis • Instruct patient on nuances of allergen avoidance diet – Packaged goods, restaurants, school, etc. • Treatment of life-threatening allergy requires instruction about recognition and management of anaphylaxis – Epinephrine is the drug of choice for treatment of anaphylaxis and should be injected promptly – Emergency plans in writing – Medical identification jewelry – Activation of emergency services (911)
- 46. Web Resources • Food Allergy and Anaphylaxis Network – www.foodallergy.org • Epipen product website – www.epipen.com • Twinject product website – www.twinject.com • Medicalert products and services – www.medicalert.org
- 47. Web Resources • Center for Food Safety and Applied Nutrition – www.cfsan.fda.gov • US Food and Drug Administration Medwatch – www.fda.gov/medwatch • American Dietetic Association – www.eatright.org • American Academy of Allergy, Asthma, and Immunology – www.aaaai.org • American College of Allergy, Asthma, and Immunology – www.acaai.org
Editor's Notes
- #1: The slide set is intended to provide primary care and emergency department physicians with an overview of the diagnosis and management of food allergic disorders. Emphasis is placed upon diagnosis and treatment of life-threatening food allergies and toward making the provider aware of patient resources. The slide set was created by Scott Sicherer, M.D. and Suzanne Teuber, M.D. with funding from the United States Department of Agriculture for a grant entitled “Multifacted Food Allergy Education Program.” Revisions were undertaken based upon validation studies. Acknowledgments to Joyce Yu, MD for assisting in those studies. We consider this slide set up to date as of September 2008. This slide set is to be considered a teaching tool for health care providers and is not a comprehensive management plan or diagnostic manual. Neither the authors nor the USDA assume any responsibility for errors or adverse outcomes associated with these teaching materials. The following are prime references used for this teaching module: Sampson HA, Munoz-Furlong A, Campbell RL. et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7. Lieberman P, Kemp SF, Oppenheimer JJ, et al. The diagnosis and management of anaphylaxis: An updated practice parameter. J Allergy Clin Immunol 2005; 115 (3):S485-523. Sicherer SH, Teuber SS. Academy Practice Paper: Current approach to the diagnosis and management of adverse reactions to foods. J Allergy Clin Immunol 2004;114(5):1146-50. Chapman JA, Bernstein IL, Lee, RE, Oppenheimer J, Nicklas RA, Portnoy, JM, Sicherer SH, Schuller DE, Spector SL, Khan D, Lang D, Simon RA, Tilles SA, Blessing-Moore J, Wallace D, Teuber SS. Food allergy: a practice parameter. Ann Allergy Asthma Immunol. 2006 Mar;96(3 Suppl 2):S1-68.
- #2: Four objectives are emphasized.
- #3: Nearly one in five individuals avoid food(s) because of a perceived “food allergy.” However, true food allergy, defined as an adverse immune response to food protein, affects 6-8 % of children and 2-4% of adults. The immune response often involves IgE antibodies that detect food proteins, but in some types of food allergy the reactions are mediated by cellular responses rather than humoral (IgE) ones. Allergic reactions to food dyes and preservatives is very uncommon. In addition to food allergy, adverse reactions to foods may occur for reasons including intolerance (a non immune response), toxic and pharmacologic reasons. Spoiled dark meat fish may induce a toxic allergic –type reaction due to release of histamine like compounds. References: Sicherer SH, Teuber SS. Academy Practice Paper: Current approach to the diagnosis and management of adverse reactions to foods. J Allergy Clin Immunol 2004;114(5):1146-50. Sicherer SH. Food Allergy. Lancet;2002;360:701-710. Sicherer SH. Sampson HA. Food Allergy J Allergy Clin Immunol, 2006;(in press) Sicherer SH. Muñoz-Furlong A, Sampson HA. Prevalence of Peanut and Tree Nut Allergy in the US determined by a Random Digit Dial Telephone Survey: A Five Year Follow-Up Study. J Allergy Clin Immunol. 2003;112:1203-7. Sicherer SH, Muñoz-Furlong A, Sampson HA. Prevalence of seafood allergy in the United States determined by a random telephone survey. J Allergy Clin Immunol 2004;114:159-65.
- #4: Sudden allergic reactions that may be immediately life-threatening are typically associated with the production of IgE antibodies. These specific antibodies arm tissue mast cells and blood basophils. When the protein cross links IgE antibodies on the surfaces of these cells, signal transduction results in release of preformed mediators (e.g., histamine) that mediate reactions.
- #5: Any food can potentially trigger a food allergic response. Most (~85%) of the significant food allergies are caused by a rather short list of foods often termed the “major allergens” (milk, egg, peanut, wheat, soy, tree nuts, fish and shellfish). Severe and life threatening food allergies are most typically associated with responses to peanut, nuts from trees, fish and shellfish. Milk, egg, wheat and soy allergies are more common in infants and children and these allergies often abate by late childhood. While not typically severe, allergic reactions to milk, egg, wheat soy and even fruits and vegetables may be severe in some persons. 85% of young children outgrow egg, milk, wheat and soy allergy by age 5 years; though peanut allergy tends to persist, 20% of young children with a peanut allergy will experience resolution of the allergy by age 5 years. References: Sicherer SH, Muñoz-Furlong A, Sampson HA. Prevalence of seafood allergy in the United States determined by a random telephone survey. J Allergy Clin Immunol 2004;114:159-65. Bock SA, Muñoz-Furlong A, Sampson HA. Fatalities due to anaphylactic reactions to foods. J Allergy Clin Immunol 2001; 107(1):191-3. Wood RA. The natural history of food allergy. Pediatrics 2003; 111(6 pt 3):1631-7.
- #6: The spectrum of food allergic disorders includes sudden reactions that are typically associated with food-specific IgE antibodies, and chronic/indolent disease that may be cell-mediated or partly associated with IgE to the causal foods. GI “anaphylaxis” refers to uncommon isolated immediate gastrointestinal reactions. Oral allergy syndrome occurs in persons who are pollen-allergic and experience mild (usually) symptoms of oral itch or mild lip swelling to raw fruits or vegetables that contain proteins that are homologous to those in the pollens. Heating/cooking typically denatures the proteins and so these symptoms are not typically associated with cooked fruits or vegetables. Food-associated, exercise induced anaphylaxis refers to a syndrome where eating a particular food (sometimes any food) before exercise results in a severe allergic reaction. Wheat and celery are typical associated triggers. This teaching module will not emphasize the diagnosis/management of the more indolent disorders, such as atopic dermatitis, eosinophilic gastrointestinal diseases, Celiac disease (which can be associated with dermatitis herpetiformis) and gastrointestinal disorders of infancy. One such disorder, food protein induced enterocolitis syndrome, is characterized by severe vomiting, diarrhea, hypotension and methemoglobinemia and is a severe, but not IgE antibody associated, form of food allergy. Reference: Sicherer SH, Teuber SS. Academy Practice Paper: Current approach to the diagnosis and management of adverse reactions to foods. J Allergy Clin Immunol 2004;114(5):1146-50.
- #7: The diagnosis of chronic disorders caused by food allergy is beyond the scope of this tutorial, but is complicated by the lack of simple diagnostic tests. In regards to IgE antibody associated allergic reactions, the clinician must determine, by the history, the likelihood of a food allergy (as compared to another disorder) and the potential causal food. Tests for food-specific IgE antibodies are very sensitive, but clinical history must be considered to improve the specificity of the test. However, many persons may test positive to foods that are not causing them any disease, making the history a very important aspect of the evaluation and emphasizing that the tests are not appropriate for screening. Reference: Sicherer SH, Teuber SS. Academy Practice Paper: Current approach to the diagnosis and management of adverse reactions to foods. J Allergy Clin Immunol 2004;114(5):1146-50.
- #8: The history may reveal that a food allergic reaction was likely (typical symptoms occurring promptly following ingestion of a trigger food) and may disclose possible triggers. Skin prick tests are typically performed by allergists. Otherwise, serum tests, often colloquially termed “RAST tests” can be used to detect serum food-specific IgE antibodies. Unlike skin tests, antihistamines do not affect the serum IgE test results. A positive IgE test to a suspected food may confirm the allergy. However, in some circumstances, dietary elimination and physician-supervised oral food challenge may be needed to confirm a diagnosis if the laboratory tests and history are not conclusive. Such testing is usually pursued by an allergist. Reference: Sicherer SH, Teuber SS. Academy Practice Paper: Current approach to the diagnosis and management of adverse reactions to foods. J Allergy Clin Immunol 2004;114(5):1146-50.
- #9: Here are summarized a few important points about allergy tests. Depending upon the serum test ordered, various units may be reported such as kilo-units, counts, or classes. In general, the greater the test level, the more likely the result may reflect a true allergy. Allergy skin test size and level on serum tests generally correlate well. However, the degree of positive allergy test result does not reflect severity of an allergy. A person with a “low level” result could have a more severe reaction than a person with a higher number on the test. Various factors such as cross-reactive proteins, digestion, immune responses and many other factors determine whether a true allergy exists and so many people could test positive to a food they will tolerate. Therefore, the clinical history is vital for interpreting tests appropriately. A positive test does not always indicate a clinical reaction and a negative test is sometimes found in persons who develop a reaction upon ingestion. Interpretation of the tests must therefore consider likelihood of allergy (prior probability) determined by a clinical history.
- #10: Anaphylaxis usually occurs rapidly and can be potentially fatal. It can be caused by foods, insect venom, drugs, and other triggers, but food allergy is the most common cause for anaphylaxis outside of a hospital setting. Sometimes, initial symptoms abate and recur a few hours later (biphasic response), or persist for many hours. References: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7. Lieberman P, Kemp SF, Oppenheimer JJ, et al, The diagnosis and management of anaphylaxis: An updated practice parameter. J Allergy Clin Immunol 2005; 115 (3):S485-523. Bock SA, Muñoz-Furlong A, Sampson HA. Fatalities due to anaphylactic reactions to foods. J Allergy Clin Immunol 2001; 107(1):191-3. Sampson HA, Mendelson LM, Rosen JP. Fatal and near-fatal anaphylactic reactions to food in children and adolescents. N Engl J Med 1992; 327:380-4.
- #11: Fatalities have been associated with the delayed use of epinephrine and certain high risk groups such as teenagers and individuals with asthma. Though one may expect to see urticaria during an allergic reaction, it is possible to have anaphylaxis without urticaria. References: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7. Lieberman P, Kemp SF, Oppenheimer JJ, et al, The diagnosis and management of anaphylaxis: An updated practice parameter. J Allergy Clin Immunol 2005; 115 (3):S485-523. Bock SA, Muñoz-Furlong A, Sampson HA. Fatalities due to anaphylactic reactions to foods. J Allergy Clin Immunol 2001; 107(1):191-3. Sampson HA, Mendelson LM, Rosen JP. Fatal and near-fatal anaphylactic reactions to food in children and adolescents. N Engl J Med 1992; 327:380-4.
- #12: An expert panel convened by the National Institutes of Health identified 3 criteria that, when fulfilled, has a high likelihood to represent anaphylaxis. Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol Feb 2006;117:391-7.
- #13: Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol Feb 2006;117:391-7.
- #14: Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol Feb 2006;117:391-7.
- #15: Epinephrine is the drug of choice for anaphylaxis. Intramuscular injection into the anterior-lateral thigh has been noted to provide higher and quicker peak levels although the subcutaneous route has been used successfully as well. Intravenous epinephrine may be indicated for severe hypotension or shock, but carries a higher risk for cardiac dysrythmias. Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7. Simons FE, Gu X, Simons KJ. Epinephrine absorption in adults: Intramuscular versus subcutaneous injection. J Allergy Clin Immunol 2001;108(5 part 1)871-3.
- #16: In addition to epinephrine, standard adjunct therapies include antihistamines such as H1 and H2 blockers, beta-2 adrenergic agents, and corticosteroids. However, it should be noted that most of these adjunct medications have not been prospectively studied in the setting of anaphylaxis. Antihistamines have a slow onset of action and do not affect blood pressure. Therefore, antihistamines are not first line therapy for anaphylaxis. H2 blockers may add efficacy to H1 blockers, but the primary effect is upon urticaria and angioedema. Due to their slow onset of action, corticosteroids are also not first line therapy for anaphylaxis but their use is presumed to reduce the likelihood of biphasic/protracted response (equivalent 1-2 mg/kg /dose methylprednisolone every 6 hours). Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol Feb 2006;117:391-7.
- #17: Further treatment options include oxygen, fluid boluses, vasopressors, and glucagon. Glucagon may improve the efficacy of epinephrine in persons with recalcitrant anaphylaxis on beta-blocker therapy. Persons experiencing anaphylactic shock should be positioned lying down with raised extremities to promote an increase in intravascular volume centrally to vital organs, if safe and possible to do so. Deaths have been reported when a person in anaphylactic shock was raised to an upright position, presumably due to loss of circulatory volume to the lower extremities. Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol Feb 2006;117:391-7. Pumphrey RSH. Fatal posture in anaphylactic shock. J Allergy Clin Immunol 2003;112(2):451-2.
- #18: Studies show a wide range of time to onset of biphasic reactions. Experts suggest a 4 to 6 hour observation period in most cases, but a longer period if initial symptoms were more severe. Reference: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7.
- #19: Once a diagnosis of anaphylaxis is made, advice for dietary avoidance and information about emergency treatment must be provided to patients. Avoidance will be reviewed in subsequent slides and includes meals taken in and outside of the home and avoidance of unexpected exposures in cosmetics or cross contact Reference: Sicherer SH, Teuber SS. Academy Practice Paper: Current approach to the diagnosis and management of adverse reactions to foods. J Allergy Clin Immunol 2004;114(5):1146-50.
- #20: Avoidance of a food allergen is often difficult and requires extensive patient education. Different problems and pitfalls may arise in various circumstances where meals are acquired. A small amount of ingested food allergen can sometimes trigger an allergic reaction for sensitive individuals. Therefore, trace amounts of allergen that may enter food in cross contact during preparation may become important. Patients must be educated about avoidance issues for purchasing manufactured products and for food obtained in restaurants and elsewhere. Food labels must be read each time because ingredients may change, and patients should be taught the limitations of labels (next slide). Persons on restricted diets may need nutritional counseling and supplementation to avoid nutritional deficits. The resources listed provide information on these topics.
- #21: Legislation requires that “major allergens” be listed on manufactured products either in the “Contains” list or as a parenthetical inclusion. However, it is important to have patients read the label carefully each time they purchase products because ingredients may change. Specific nuts, fish, or shellfish must be listed and companies may continue to use scientific terms as long as the equivalent plain English word is listed.
- #22: Allergens that are not listed among the “major” allergens may not be disclosed, so patients may need to call manufacturers to determine certain ingredients when ambiguous terms (e.g., spices) are used for allergens that are not “major allergens.” In addition, labels may indicate a “chance” of allergen contamination. An important resource is The Center for Food Safety and Applied Nutrition (www.cfsan.fda.gov). This Division of the US Food and Drug Association assists with matters of public health and policy regarding food safety, including allergy. Information about labeling and other food allergy issues are posted on this site. There are also links for reporting problems with foods (for example undeclared allergen) through www.fda.gov/medwatch/.
- #23: Allergic reactions may occur in restaurants for a variety of reasons. Shared utensils or equipment (fryers, pans) may result in cross contact of food with an allergen. It is important for patrons and restaurant staff to maintain a clear line of communication to ensure a safe meal is obtained. A “Chef Card” disclosing the allergy may be helpful. Patients should disclose that they have an allergy, not just a distaste for a food. Resource: The Food Allergy & Anaphylaxis Network (800-929-4040) www.foodallergy.org.
- #24: School is another common location for food-allergic reactions. A variety of strategies have been recommended to reduce the risk of reactions. A few are listed here. Further resources are shown on the following slides. References: Sicherer SH, Furlong TJ, DeSimone J, Sampson SH. Peanut allergic reactions in schools. J Pediatr 2001;138:56-5. Nowak-Wegrzyn A, Conover-Walker MK, Wood RA. Food-allergic reactions in schools and preschools. Arch Pediatr Adolesc Med. 2001;155(7):790-5. The American Academy of Allergy, Asthma and Immunology. Board of Directors. Anaphylaxis in schools and other child care settings. J allergy Clin Immunol 1998;102:173-76.
- #25: A plan must be in place to ensure that the school is able to respond appropriately to an anaphylactic reaction
- #26: The Food Allergy & Anaphylaxis Network is a lay organization that provides a number of educational programs for schools and families. “FAAN” is a major resource for individuals and families with food allergies. The organization has an internationally recognized medical advisory board that oversees its materials. FAAN provides parent educational conferences, educational books and videos for parents covering essentially every topic in managing food allergy, comprehensive programs for preschools, schools and camps, books for children and teens, research updates and much more. FAAN is also active in education, research and policy regarding food allergy. The site is an excellent resource to stay “up to date” on research and policies regarding food allergy and a newsletter is offered as well. There is also a specific newsletter and website for children and teens.
- #27: Several organizations have endorsed a list of recommendations regarding food allergy safety for schools. These recommendations are directed to the school, parents and students.
- #28: In addition to ingestion of an allergen, patients should be instructed about addition ways that exposure may result in allergic reactions. However, anaphylaxis is much more likely to be the result of ingestion exposures (unless kissing is passionate). References: Hallett R, Haapanen LA, Teuber SS. Food allergies and kissing. N Engl J Med 2002;346 (23):1833-4. Simonte SJ, Ma S, Mofidi S, Sicherer SH. Relevance of casual contact to peanut butter in peanut-allergic children. J Allergy Clin Immunol 2003;112:180-83.
- #29: Though prescription of self-injectable epinephrine is clearly indicated for a person who has experienced anaphylaxis to a trigger they may encounter in the community, there are other potential indications that are more dependant upon specific circumstances. A physician/patient may discuss the utility of having self-injectable epinephrine available for individuals who are at increased risk for anaphylaxis. The package insert indicates dosing at particular weight intervals, but experts have advised that dosing may vary as clinically indicated to avoid significant under-dosing. In the event that more than one dose is needed while the victim is not under medical care, availability of more than one self-injected dose has been advised. References: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7. Sicherer SH. Simons FER. Quandaries in prescribing an emergency action plan and self-injectable epinephrine for first-aid management of anaphylaxis in the community. J Allergy Clin Immunol 2005;115:575-83.
- #30: It is important to review the technique and indications for use of self-injectable epinephrine. The advice may vary according to the patients individual circumstances. Fatalities have occurred in association with delays in injecting epinephrine, so erring on the side of caution, that is, to inject epinephrine promptly in the event of likely anaphylaxis, is suggested. It is important to review the technique of administration and remind patients about proper storage (not refrigerated, not in direct heat) and to renew prescriptions. References: Sampson HA, Munoz-Furlong A, Campbell RL. Et al. The second symposium on the definition and management of anaphylaxis: Summary report. J Allergy Clin Immunol 2006;117:391-7. Sicherer SH. Simons FER. Quandaries in prescribing an emergency action plan and self-injectable epinephrine for first-aid management of anaphylaxis in the community. J Allergy Clin Immunol 2005;115:575-83. The American Academy of Allergy, Asthma and Immunology. Board of Directors. Anaphylaxis in schools and other child care settings. J Allergy Clin Immunol 1998;102:173-76.
- #31: Written materials are available to assist in providing a written emergency action plan to patients. Medical identification jewelry is suggested. In the event of anaphylaxis, emergency services (e.g., calling 911) should be activated.
- #33: Because diagnosis may require advanced testing, and instructions on avoidance and treatment may be complex, referral to a Board-Certified, or equivalent, allergist is suggested. The professional organizations listed have search engines to locate Board-Certified allergists by zip code.
- #34: The following case examples will illustrate several of major points made in this learning module.
- #36: Learning Objective: The first step toward a proper diagnosis is a careful medical history. Sarah usually tolerated a variety of tree nuts, including the one initially mentioned as an ingredient in the cookie. Having additional information about the cookie ingredients allowed for more directed testing.
- #38: Learning objective: The history is an important component to an emergency action plan. Erring on the side of caution and injecting epinephrine in the community setting is advisable.
- #40: Learning Objective: Various illnesses may appear similar to anaphylaxis. Recognizing the circumstances of a reaction may aid in proper diagnosis.
- #42: Learning Objective: Fatalities have been documented for anaphylaxis that occurs without urticaria.
- #44: Learning Objective: Anaphylaxis may follow a biphasic course so additional observation is needed. Review of possible triggers and prescription of an action plan is needed (pending more definitive evaluations).