Food Allergies

Question 1

difference between food allergy and food sensitization

Answer 1

allergy means you have antibodies present and have a response

sensitization means you have the antibodies present in the skin but not necessarily have an allergic response

Question 2

Mechanism of first response to allergen

Answer 2

allergen picked up by dendritic cell
allergen presented to Th cells and Th cells mainly become Th2 cells
Th2 cells then secrete IL-4 to promote class switching in B cell antibodies to IgE
IgE is made by plasma cells
Specific IgE binds to the FceRi receptor on mast cells

Question 3

Mechanism of repeat exposure to allergen

Answer 3

allergen binds to the IgE antibodies on the FceRI receptors of mast cells
Causes release of cytokines, lipids and vasoactive amines

Question 4

FceRI receptor on mast cells importance and composition

Answer 4

important for binding the IgE

has alpha beta and gamma chains, alpha binds IgE, beta and gamma for signal transduction

Question 5

Mast cell products and location

Answer 5

histamines, enzymes (tryptase), lipid mediators like prostaglandins and leukotrienes, and cytokines (TNF)

in tissues

Question 6

Basophil cell products and location

Answer 6

similar to mast cells but no tryptase
also make IL-4

in blood

Question 7

Eosinophils products, location, and function

Answer 7

more toxic things like hydrolases, peroxidases

blood

late phase allergic response

Question 8

How to activate a mast cell FceRI receptor?

Answer 8

allergen must crosslink between two receptors with antibody bound

Question 9

Mast cell mediator effects? (6)

Answer 9

vasodilation, vascular leak, bronchoconstriction, intestinal hypermotility, inflammation, tissue damage

Question 10

Characteristics of type I acute immediate response

Answer 10

vasodilation, swelling, itching, bronchoconstriction, intestinal hypermotility

Question 11

Characteristics of type I late phase response

Answer 11

production of cytokines for inflammation and recruitment of inflammatory cells like eosinophils, basophils and T cells

Question 12

problem with allergy testing?

Answer 12

lots of false positives

Question 13

skin prick testing information

Answer 13

prick with allergen and should see reaction within 15 minutes

if positive will have the spots

no antihistamine therapy for 3-7 days prior!

Question 14

in vitro IgE testing information

Answer 14

allergen ELISA with patient serum containing possible IgE

perform if cant do skin prick because of antihistamines

Question 15

food induced anaphylaxis criteria

Answer 15

cutaneous symptomes (hives or angioedema) and respiratory symptoms and/or cardio problems

Also can have cutaneous, respiratory and cardio combined with GI or low BP

DONT HAVE TO HAVE HIVES

Question 16

oral allergy syndrome

Answer 16

pollen-food allergy syndrome…when you eat a food your body is tricked into thinking youre eating a bunch of the allergen…pollen, ragweed and birch on common foods

will have oral reaction…tingly

Question 17

oral allergy syndrome diagnosis test

Answer 17

prick food causing problem then prick the person and see if have reaction

Question 18

food dependent exercised induced anphylaxis

Answer 18

eat food like wheat, nuts or shellfish and then exercise induces allergic response, if dont exercise you are fine

Question 19

delayed allergic reactions to mammalian meat information

Answer 19

delayed response after eating red meat or pork…

due to IgE antibody against alpha-gal from mammals

associated with lone star tick bites