Hypersensitivity

Question 1

Types of hypersensitivity reactions

Answer 1

immediate: (antibody-mediated)
type i,ii,iii

delayed: (cell-mediated)
type iv

Question 2

Type i: IgE- mediated

Answer 2

induced by allergens
1. sensitizing dose: first exposure
2. immune system produce IgE antibodies
3. IgE attach to mast cells and basophils (WBCs)
4. the next exposure to that antigen cross links IgE molecules
5. cells release granule content

Question 3

Granules contain what mediators that are released during hypersensitivity?

Answer 3

Histamine
Leukotrienes
Prostaglandins
Cytokines

Question 4

Histamine

Answer 4

cause smooth muscle cell constriction

Question 5

Leukotrienes

Answer 5

potent smooth muscle constriction

Question 6

Prostaglandins

Answer 6

constrict bronchial tubes

Question 7

Cytokines

Answer 7

stimulate inflammation

Question 8

Atopic disease (Atopy)

Answer 8

most common form of Type 1 hypersensitivity

common (seasonal) allergy
cause: pollen

year-round allergies can result from chronic exposure to allergens

Question 9

food allergy symptoms

Answer 9

swollen lips
abdominal cramps
nausea
diarrhea
hives
anaphylaxis

Question 10

physical factors causing hypersensitivity

Answer 10

extreme temp
sunlight
sweating

Question 11

big eight food allergens

Answer 11

eggs
milk
fish
wheat
shellfish
tree nuts
peanuts
soy

Question 12

Asthma

Answer 12

can be triggered by allergic reactions

cause: airborne allergens, exercise, cold temp

Question 13

Asthma
Degranulation of mast cells

Answer 13

they release mediators into the lower respiratory tract causing:
Bronchoconstriction
vasodilation
mucus buildup

Question 14

Asthma
recruitment of eosinophils and neutrophils into the lower respiratory tract causes:

Answer 14

tissue injury
airway blockage

Question 15

anaphylactic shock

Answer 15

caused when hypersensitivity becomes systemic

Question 16

anaphylactic shock s/s

Answer 16

1.small veins constrict
2.capillary permeability increases
3.fluid moves into tissues
4.drop in blood pressure
5.edema
6.contractions in the GI tract and bronchial muscles cause cramps and shortness of breath

Question 17

possible result of anaphylactic shock

Answer 17

death by asphyxiation in 10-15 mins

Question 18

treatments for type 1 hypersensitivity

Answer 18

avoidance

pharmacology
-antihistamine
-corticosteroids
-epinephrine
-antibody therapy

desensitization therapy

Question 19

desensitization therapy

Answer 19

cause production of IgG antibodies that neutralize allergens
(Blocking antibodies) which blocks the reaction

Question 20

type ii cytotoxic hypersensitivity

Answer 20

abtibody-mediated cell destruction
1. IgG reacts with antigens on cells
2. cells are destroyed by activated complement or by NK cells

Question 21

hemolytic disease of fetus/newborn

Answer 21

when incompatible blood types are mixed, agglutination may occur and complement can be activated, leading to RBC destruction

Rh disease can lead to stillbirth or jundice

Question 22

type iii immune complex hypersensitivity

Answer 22

problem is the immune complexes which get stuck and the complement system gets activated resulting in tissue damage
1.antigen-antibody aggregates form
2.complment is activated
3.tissue damage results

Question 23

type iv cell mediated (delay-type) hypersensitivity

Answer 23

induration (thickening of skin tissue) due to cellular infiltration of immune lymphocytes

surrounded by erythema

response to certain microbial antigens

this is why TB skin test take so long (their delayed)

Question 24

contact dermatitis

Answer 24

develops after exposure to an allergen

repeated exposures cause:
drying of skin
erythema
scaling

Question 25

tick bites can cause meat allergy

Answer 25

lone star tick

1.bite exposes person to alpha-galactose(anitgen found in mammalian meat, cows milk, gelatin)

2.IgE antibody develops

Question 26

result of the lone star tick bite

Answer 26

hives
swelling

*anaphylactic response a few hours after eating beef or pork