Hypersensitivity Flashcards
what is hypersensitivity
exaggerated innaprotpriate adaptive immune response
what can be a result of hypersensitivity
inflammation and tissue damage
what can hylprsenstiiy be provoked by
many antigens
who will a hyper reaction occur
no manifest on 1st contact with Ag usually appears on the rcontact
what are the classes of hyper
1, 2, 3, 4
how are types 1 2 3 mediated
antibody
how is type 4 mediated
by T cells and macrophages
what is type 1 hyper
IgE response to innocuous enviro antigens
what are some examples of innocuous enviro antigens
pollen
dust mites
animal hair
latex
what doe IgE bind to
F(epsilon)RI on mast cells bind very tight as high affinity
what does the second encounter with allergen do
triggers release inflam mediators
what does type 1 produce
acute inflam reactions within minutes with symptoms such as asthma
what are some major allergens for type 1 hyper
house mites a
pollen - ragweed
what happens when allergic response release of
histamine
prostangladins
other mediators
leukotrienes
what are som treatments for type 1 hyper
avoidance
sodium chromoglycate
anti histamines
desnsitiitaiton
what is anaphltactic shock
severe type 1 reactions with systemic symptoms life threat
what are some symptoms of anaphylactic shock
wheeze swelling of face laryngopharynx nausea dizziness
how is anaphylactic shock treated
adrenaline immediately
what is imp for dentist to know anaphylactic shock
type 1 reactions to anaesthetics can occur can create generalised anaphylaxis so always have adrenaline near
what is type 3 hyper
antibody dept cytotoxic hyper
when does type 3 occur
12-18 hours after Ab expo
what causes type 3
IgM or IgM binds to either self antigen or foriegn causing phagocytosis kileer cell active
what is a primary example of type 3
blood transfusion reaction when ABO incompatible blood is transferred
what are some symptoms of blood tran incompatible
fever hypotension nausea vomiting pain in back or chest
what is another example of type 3
haemolytic disease of newborn
what is haemolytic disease in newborn
when rhesus d in mother and child don’t match causing attack in future children
what is seen with a baby who has haemolytic disease
swollen abdomen due to enlarged liver and spleen du to RBC destruction
elevated bilirubin
facial petechia
when does type 3 extrinsic allergic alveoli’s occur
18-24 hours
what is extrinsic allergic alveoli’s mediated by
persistence and depo of antibody antigen immune complexes
what is IC clearance influenced by
route of Ag expo
dose Ag
size IC
binding of Ag direct to tissues
type 4 hyper said to be
delayed occurs in 48-72 hour
what are the three types of type 4
contact 48-72 hours
tuberculin 48-72
granulomatous 21-28 days
what is type 4 mediated by
T cells and macrophages
what are the two phases of type 4
sensitisation
elicitation
what is sensitisation
Ag encoures dendritic cell in skin
migrates to lymph node
presents Ag to CD4+T cell
what is elicitation
Ag enouctered
memory T cell triggered
inflamation
what are some dental materials that can elect a type 4 response
amalgam
gold
mercury
resin based
what si contact type 4
eczetamus recation POC - nickel or poison ivy
what is tuberculin type 4
skin swelling develops after intradermal expo
what is granulotamotu type 4
granuloma for - aggregation and prolif macrophages press for weeks
