Food Allergy Module 2

Question 1

9 top food allergens

Answer 1

Peanuts
Tree nuts
Eggs
Fish
Shellfish
Soy
Wheat
Dairy
Sesame (new)

Question 2

symptoms of food allergy

Answer 2

Itching or swelling in your mouth
Vomiting, diarrhea, or abdominal cramps and pain
Hives or eczema
Tightening of the throat and trouble breathing
Drop in blood pressure

Question 3

NIAID definition

Answer 3

An adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food.

Question 4

immune-mediated reaction to food what cells are involved

Answer 4

IgE (antibodies)
Non-IgE (immune cells)
Eosinophils
T cells
Mast cells
Mixed (antibodies and cells)
Should not be confused with INTOLERANCE (unknown or other mechanism)

Question 5

allergies must be __ with repeat exposure

Answer 5

allergies must be reproducible with repeat exposure

Question 6

allergens are __ or __ and are generally __ and __

Answer 6

allergens are proteins or glycoproteins and are generally heat resistant and acid stable

Question 7

major allergenic foods account for >__% of food allergy
includes __ and __

Answer 7

major allergenic foods account for >90% of food allergy
includes egg whites and tree nuts also top 9!

Question 8

allergies most common in children:
__% outgrow by __ years

Answer 8

allergies most common in children: milk, egg, soy, and wheat
50% outgrow by 5-7 years

Question 9

allergies that persist into adulthood:
__% outgrow

Answer 9

allergies that persist into adulthood: peanut, tree nuts, finned fish, shellfish
20% outgrow peanut, 1% outgrow tree nuts

Question 10

2 treenut cross-reactivities

Answer 10

Cashew and pistachio
Pecan and walnuts

Question 11

cross-sensitization
cross-reactivity
cross contamination

Answer 11

cross-sensitization: have antibodies
cross-reactivity: sensitivty to both cow’s milk and goat’s milk
cross contamination: kitchen issue

Question 12

peanuts are cross-reactive with

Answer 12

other legumes: peas, lentils, beans

Question 13

oral allergy syndrome most common in

Answer 13

adults, but seen in kids

Question 14

clinical features of OAS

Answer 14

rapid onset oral pruritus
rarely progressive

Question 15

epidemiology of OAS

Answer 15

prior sensitization to pollens

Question 16

key foods in OAS

Answer 16

RAW fruits and vegetables

Question 17

cause of OAS

Answer 17

cross reactive proteins in pollen and food

Question 18

how does OAS work only with raw things?

Answer 18

allergens are heat sensitive, cooked versions are usually okay

Question 19

birch cross reactivity

Answer 19

Apple, carrot, celery, cherry, pear, hazelnut

Question 20

ragweed cross reactivity

Answer 20

Banana, cucumber, melons

Question 21

grass cross reactivity

Answer 21

Melon, tomato, orange

Question 22

mugwort cross reactivity

Answer 22

Melon, apple, peach, cherry

Question 23

clinical history consistent with food allergy

Answer 23

Immediate onset
Specific symptoms as above
No history of tolerating consistent prior ingestion
Common food allergens are COMMON

Question 24

clinical history NOT consistent with food allergy

Answer 24

Delayed onset
Symptoms NOT as above
GI (more lower than upper), neurologic, behavioral, vague rashes
Recurring hives
Chronic asthma or nasal allergy symptoms Occurring inconsistently
History of tolerating consistent prior ingestion
Has ingested numerous times previously
Not a common food allergen (strawberries, kiwi, tomatoes)

Question 25

recommended tests for allergies

Answer 25

Skin prick test ImmunoCAP-RAST Serum IgE testing Elimination diet: strict, 2-6 weeks, must reintroduce if no change GOLD STANDARD = oral food challenge

Question 26

NOT recommended tests for allergies

Answer 26

Patch tests Intradermal tests Unproven tests (IgG, kinesiology, VEGA, NAET, ALCAT, etc.)

Question 27

ImmunoCAP-RAST testing steps

Answer 27

1. patient's serum with IgE is added 2. enzyme-labeled antibodies added 3. developing agent is added 4. fluorescence is measured

Question 28

positive ImmunoCAP-RAST test means

Answer 28

sensitization

Question 29

ImmunoCAP-RAST test

Answer 29

- Many false positives BAD screening test >50% of people test + for foods they are not reactive to (more common in older children and adults) - Moderate sensitivity and specificity (“accuracy”) Sensitivity and specificity varies by food - Higher levels are more associated with clinically relevant “positive” tests - Good negative predictive value Be careful of non-IgE food allergy = NOT equivalent to a diagnosis of allergy USE clinical HISTORY to interpret (aka “pre-test probability”)

Question 30

positive IgE and no symptoms =

Answer 30

sensitivty

Question 31

sensitivity process

Answer 31

Eat peanuts Dendritic cells present peanut particles to peanut specific T cells Th2 cells stimulate B cells to make antibodies specific for peanuts Peanut specific IgE antibodies bind mast cells and go to recognize peanut, nothing happens

Question 32

positive IgE and symptoms

Answer 32

allergy

Question 33

allergy process

Answer 33

IgE on allergy mast cells binds peanut protein, releases histamines, causes symptoms

Question 34

management and treatment of allergies

Answer 34

1. strict dietary avoidance 2. management of acute allergic reactions: epinephrine, benadryl, zyrtec 3. oral food challenges 4. immunotherapy

Question 35

avoidance

Answer 35

1. STRICT avoidance 2. label reading 3. precautionary allergy labeling (PALs) may contain, same facility

Question 36

treating anaphylaxis: epinephrine dose

Answer 36

0.01 mg/kg (max 0.5 mg)

Question 37

treating anaphylaxis: epinephrine route

Answer 37

intramuscular Higher and quicker peak serum levels compared to subcutaneous

Question 38

treating anaphylaxis: epinephrine location

Answer 38

anterior, lateral thigh (vastus lateralis) Higher and quicker peak serum levels compared to deltoid

Question 39

treating anaphylaxis: epinephrine frequency

Answer 39

~5-15 minutes (adjusted clinically)

Question 40

treating anaphylaxis: adjunct treatments

Answer 40

Antihistamine (H1 and H2 Blockers) *NOT FIRST-LINE THERAPY* Slow onset (e.g. 30 minutes) Helpful for urticaria, angioedema, pruritus Little effect on blood pressure Addition of H2 blockade (may improve treatment of cutaneous manifestations) WILL NOT STOP ANAPHYLAXIS Adrenergic agents Inhaled beta-2 agonists may be useful for bronchospasm refractory to epinephrine Corticosteroids *NOT FIRST-LINE THERAPY* May prevent protracted/biphasic course but not proven

Question 41

treating anaphylaxis: adjunct/advanced treatment options

Answer 41

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”)

Question 42

reaction does not indicate

Answer 42

allergy

Question 43

what is the main way to diagnose IgE-mediated allergies

Answer 43

clinical history

Question 44

pathogenesis of food allergy is

Answer 44

still unknown