Anaphylaxis

Question 1

Describe process of IgE mediated anaphylaxis

Answer 1

Initial sensitisation to antigen causes B cell to produce IgE
IgE binds to surface of mast cell or basophil
Subsequent exposure to same antigen, antigen bridges gap between two antibody molecules and causes degranulation of the cell with release of histamine + others
-> bronchoconstriction, mucus secretion, decreased cardiac contractility, increased vascular permeability, vasoconstriction of coronary and peripheral arteries, venule vasodilation

Question 2

What substances cause non-IgE mediated anaphylaxis?

Answer 2

Opioids
Radiocontrast media
Temperature
Idiopathic

Question 3

What three criteria make anaphylaxis likely?

Answer 3

Sudden onset symptoms with rapid progression
Life threatening A and or B/C problem
Skin and/or mucosal changes

Question 4

What drug treatment anaphylaxis?

Answer 4

IM adrenaline 0.5ml (500 mcg), 1/1000 solution (1mg/ml)
IM or slow IV chlorphenamine 10mg
IM or slow IV hydrocortisone 200mg
Salbutamol