analphylactic shock

Question 1

signs and symptoms of anaphylaxis

Answer 1

swelling of conjunctiva 
runny nose
swelling of lips tongue throat 
fast/slow HR 
low bp 
hives
itchiness
swelling 
pelvic pain 
light headed 
loss of consciousness
confusion
headache
anxiety 
SOB 
wheezes 
hoarseness
pain with swallowing 
cough 
crampy abdo pain 
diarrhea 
vomiting 
loss of bladder control

Question 2

what is anaphylaxis

Answer 2

acute
type 1 hypersensitivity rn - systemic
life threatening
IgE mediated response to allergen throughout the body

Question 3

IgE response

Answer 3

important against parasitic infections

Question 4

normal lymphocyte activation

Answer 4

antigen binds to surface of IgM on lymphocytes
stimulate prolif and secretion of Ab
Ab is IgM and then IgG as response progresses

Question 5

lymphocyte activatation in Type 1 hypersensitivity

Answer 5

activation of CD4+ T helper cells (TH2)
IgE production
IgE binds to IgE receptors on mast cells
subsequent stimulation of mast cells by exposure = anaphylactic response

Question 6

allergen

Answer 6

antigen that causes an allergic type of IgE mediated response

Question 7

mast cells

Answer 7

widely distributed in epithelial mucosae - resp and intestinal and connective tissue - under the skin
contain granules with histamine and leukotrienes
secreted following antigen binding to IgE

Question 8

action of inflammatory mediators

Answer 8

act on bv and sm
in connective tissue histamine = dilation of vessels = blood flow to surface = fluid move out of blood - oedema
mucosae - constriction of airways and sm in intestines
net effect depends on if local/systemic

Question 9

skin allergy

Answer 9

stim of connective tissue mast cells = vasodilation = red skin rash and oedema = raised appearance
rash called urticaria - from nettles

Question 10

use of localised skin reaction

Answer 10

allergy testing

allergens injected by pin prick to see if have wheal and flare reaction

Question 11

substances that cause skin allergies

Answer 11

animal hair
proteins in natural latex
chemicals
substances in insect and plant stings

Question 12

hay fever and asthma

Answer 12

allergen inhaled
principle site of action - mucosal mast cells in resp system
if in nasal passage = oedema = irritation = mucous secretion - allergic rhinitis
if reac bronchioles - contraction of sm = reduced diameter, inf and increased mucous - asthma - difficulty breathing in and mainly out

Question 13

substances causing hay fever and asthma

Answer 13

pollen
faeces of dust mites
proteins from animal hairs

Question 14

food allergy

Answer 14

ingested
mucosal mast cells in GI tract
stimulation of sm = vomiting and diarrhoea
if it can be absorbed and passed to the blood stream - rash and itching

Question 15

substances that cause food allergies

Answer 15

peanuts 
other nuts and legumes - soya 
shellfish
milk
eggs 
wheat

Question 16

anaphylaxis

Answer 16

systemic result to allergen 
cause immediate response throughout body
not common 
potentially fatal 
medical emergency
dilation of peripheral bv = rash and oedema and drop in bp affectiung organ function - shock 
constriction fo bronchi = difficulty breathing
increase in resp rate and HR 
nausea, ab cramps, diarrhoea

Question 17

treatment of anaphylaxis

Answer 17

emergency treatment - aimed at hypotension and underlying inf
patient laid down with feet raised - improve blood flow to head and trunk
adrenaline constrict peripheral vessels - redirect blood flow to organs
IV drip - control BP
antihistamines and antiinf corticosteroids
if breathing problems persist - oxygen and bronchodilators needed by inhaler

Question 18

requirement for substances to cause anaphylaxis

Answer 18

substances have to eb able to pass freely through the body

Question 19

substances that can cause anaphylaxis

Answer 19

penicillin - especially if IV
local anesthetics and x ray contrast agents
venom in bee/wasp stings
peanuts - allergen can be absorbed fast enough to cause systemic effects

Question 20

long term treatment of anaphylaxis

Answer 20

avoid allergen

adrenaline in self injection pen for use in emergency

Question 21

cause of anaphylaxis

Answer 21

can have a genetic predisposition

Question 22

sensitisation

Answer 22

1st meeting with allergen = no clinical effect

2nd = clinical effect

Question 23

process of immune response in 1st exposure

Answer 23

APC start reaction
present antigen to T helper cell
naïve T helper turns to primed Th
stimulatory molecules T4, 5 , 10 stimulate type 2 Th
maturation of type 2
can produce interleukins - inf response amplified
induce maturation of other molecules eg Ig 4 - B cells, Ig5 - eosinophils - degranulation
B cell produce eosinophils
go on surface of mast cells bound to FcE receptors - multiple bonds - sensitisation

Question 24

what determines the type of Th cells

Answer 24

the proteins around it

Question 25

process of immune response in 2nd exposure

Answer 25

APC present to Type 2 Th 
make IL 4, 5, 10 
present to B cell and eosinophil 
mast cell has IgE and antigen binding 
mast cell degranulates 
release histamine = vasodilation - increase perm of vessels = hives and oedema 
Bp decrease
SOB from constriction of airway also brain starved of O2

Question 26

early stage anaphylaxis

Answer 26

takes place in minutes

Question 27

late stage anaphylaxis

Answer 27

amplification after 8, 10, 12 hours
basophils, mast and eosinophils attracted
fatty acids
B4 and C4 - amplify effect on bronchi and vessels - attract inf molecules even if the antigen is gone

Question 28

what determines the clinical effects

Answer 28

histamine

Question 29

what do corticosteroids do

Answer 29

contrast inflammatory molecules

Question 30

summary of sensitisation

Answer 30

APC produce IL 4, 5, 10

Th then produce IL 4 5 10

Question 31

interleukin 4 and 5

Answer 31

4 - B cell - IgE - bind to mast cell

5 - eosinophil

Question 32

what determines if the reaction is local/systemic

Answer 32

depend of load of antigen and genetic predisposition