Anaphylaxis

Question 1

What is it?

Answer 1

IgE mediated degranulation of mast cells and basophils

Effects include:
- widespread vasodilation- hypotension
- increased vascular permeability- oedema and swelling
- smooth muscle contraction- bronchospasm

Question 2

What are the symptoms?

Answer 2

Rapid onset
Urticaria, angioedema, itching
Stridor
Wheezing
Dyspnoea
N&V
Abdo pain

Question 3

What are the investigations?

Answer 3

Serum tryptase (1-2 hours post onset)- confirms mast cell activation
Allergy- delayed investigation to identify trigger

Question 4

What is the management?

Answer 4

IM adrenaline 1:1000 500mcg

Repeat after 5 minutes
If symptoms persist after 2 doses follow refractory pathway consider IV adrenaline infusion

Question 5

What is the management in children?

Answer 5

Child 6-12 years 300mcg
Child 6 months to 6 years: 150mcg
Child <6 months 100-150mcg