Allergy and hypersensitivity

Question 1

Anaphylaxis

Answer 1

a severe reaction from type 1 hypersensitivity causes include insects, pollen, dustmite, food. Mast cells and basophils have a high concentration of iGe on their surface which are activated by allergens that trigger the cells degranulation and release of histamines, some cytokines, prostoglandins

Question 2

Treatment of type 1 allergies

Answer 2

histamine receptor reverse agonists(first and second generation
corticosteroids
Mast cell stabilizer (chromolyn and nedocromil)
a and b adrenergic receptor agonist (Adrenaline )
anti IgE antibodies (omalizumab)

Question 3

Corticosteroid and mast cell stabilizer’s

Answer 3

Corticosteroids
inhaled corticosteroid used for preventative treatment in asthma
-reduces amount of inflammatory cells, eosinophils and th2 cells also mast cells are reduced with long term use
Mast cell stabilizers
–preventative, inhaled therapy used prevent initiation of allergic response

Question 4

adrenaline and omalizumab and desensitisation

Answer 4

Adrenaline
- for moderate-sever anaphylaxis, vasoconstriction, broncodilation and increases heart rate
omalizumab
- binds to igE receptor on mast cells, decreases circulating igE and down regulates th2 cells
desensitisation
- administering high doses of allergens risk of anaphylaxis

Question 5

type 2 allergy

Answer 5

antibody dependent cellular cytotoxicity (ADCC)/complement mediated cytolysis. to kill cells via non-phagocytic : nk cells, esinophils. Anaemia, agranulocytosis.

Question 6

type 3 allergy

Answer 6

insoluble complexes of antibody and antigen that cannot be cleared by phagocytosis resulting in chronic inflammation