Anaphylaxis

Question 1

Anaphylaxis

Answer 1

Type 1 hypersensitivity
Caused by venom,food,drugs,anaesthectics,penicillin
An allergy
Activate b and T cells (Th2) causing antibody release

Question 2

Symptoms

Answer 2

Breathless
Fainting
Organ shock
puffy eyes/rash (urticaria)
Nausea
Mast cell degranulation-histamine in connective tissue-peripheral vasodilation-drop in bp-depleted o2

Question 3

Adrenaline

Answer 3

Causes peripheral vasoconstriction
Opens air ways

Causes B cells to release IgM → Th2 releases cytokines e.g. IL4 and IL13 → class switch in B cells producing IgE instead → IgE binds to Fc epsilon receptor on mast cells and basophi (not caused by adrenaline just in general)

Question 4

What type of cells cause symptoms

Answer 4

Mast cells

Question 5

What signalling molecule is involved

Answer 5

Histamine and leukotriene

Question 6

What immunoglobulin class is involved

Answer 6

IgE
Activation of cd4 T helper cells causes switch to IgE

Question 7

Medications given later

Answer 7

Steroid, bronchodilators, antihistamines

Question 8

Why is blood pressure monitored

Answer 8

Monitoring of blood pressure provides a reliable indication of recovery.

Biphasic anaphylaxis → Sometimes symptoms return within a few hours

Patients with moderate respiratory or cardiovascular compromise should be observed for to up to 8-10 hours before discharge

Question 9

Why do patients feel faint

Answer 9

Due to dramatic drop in blood pressure