Food Allergy Primer

Question 1

Oral Allergy Syndrome

Answer 1

Oral tolerance bypassed due to sensitization through respiratory route (ie Respiratory sensitization to Bet v 1 in birch pollen might lead to oral pruritus in allergic patients when eating raw apples because of cross-reactivity to a homologous apple protein, Mal d 1)

Question 2

FPIES in regards to (TGF-B and TNF-a)

Answer 2

Deficit in TGF-b1 response and excessive TNF-a response might be important pathogenic factors

Question 3

In recent studies suggest that 70% to 80% of young children allergic to milk or eggs can tolerate baked (heat-denatured) forms of the protein but not the unbaked form why is this?

Answer 3

It is suggested that these children make IgE antibodies primarily to conformational epitopes on the food proteins and represent the children who will naturally outgrow their food allergies.

Question 4

High rates of clinical cross reactivity in tree nut family?

Answer 4

walnut-pecan, almond-hazel, cashew-pistachio

Question 5

What do higher concentrations of food-specific IgE levels correlate with?

Answer 5

Correlate with an increasing likelihood of a clinical reaction but do not generally correlate very well with reaction severity.

Question 6

What is the first demonstration of IgE antibodies directed at a carbohydrate epitope leading to clinical symptoms?

Answer 6

Commins et al identified 24 adults who reported urticaria, angioedema, or anaphylaxis 3 to 6 hours after ingesting beef, lamb, or pork. These patients were all found to have positive skin test results and serum IgE antibodies to galactose-a-1,3-galactose, the carbohydrate moiety of these glycoproteins

Question 7

Heiner syndrome?

Answer 7

Rare infantile disorder characterized by pulmonary hemosiderosis triggered by milk protein, is associated with increased milk-specific IgG antibodies.

Question 8

Adverse reactions that are not classified as food allergies: host-specific metabolic disorders examples?

Answer 8

lactose in- tolerance, galactosemia, and alcohol intolerance

Question 9

Adverse reactions that are not classified as food allergies: a response to a pharmacologically active component. examples?

Answer 9

caffeine, tyramine in aged cheeses triggering migraine, and histaminic chemicals in spoiled dark-meat fish resulting in scombroid poisoning masquerading as an allergic response

Question 10

Adverse reactions that are not classified as food allergies: toxin examples?

Answer 10

Food poisoning

Question 11

Adverse reactions that are not classified as food allergies: psychologic examples?

Answer 11

food aversion and anorexia nervosa

Question 12

Adverse reactions that are not classified as food allergies: neurologic examples?

Answer 12

auriculotemporal syndrome manifested by a facial flush from tart foods or gustatory rhinitis manifested by rhinorrhea from hot or spicy foods)-can mimic food allergies.

Question 13

For IgE-mediated disorders, skin prick tests (SPTs) provide a rapid means to detect sensitization.
NPV? Specificity?

Answer 13

Negative SPT responses essentially confirm the absence of IgE-mediated allergic reactivity (negative predictive accuracy, >90%). However, a positive test response does not necessarily prove that the food is causal (specificity, <100%).

Question 14

What are examples of foods that induce exercise induced anaphylaxis

Answer 14

wheat, celery, shellfish

Question 15

what is auriculotemporal syndrome?

Answer 15

neurologic response to the spicy or tart triggers; nonpruritic erythema over the left cheek minutes after she ingests, on separate occasions, lemonade, spicy potato chips, and sour candy

Question 16

Differences in immune responses may depend on the dose of antigen ingested.
High dose tolerance?
Low dose tolerance?

Answer 16

high-dose tolerance involves deletion of effector T cells, and low-dose tolerance is the result of activation of regulatory T cells with suppressor functions.

Question 17

What are common features of MAJOR food allergen characteristics

Answer 17

water-soluble glycoproteins, 10-70 kd in size, and relatively stable to heat, acid, and proteases