Anaphylaxis

Question 1

What is it?

Answer 1

Severe hypersensitivity reaction manifesting in respiratory difficulty and/or cardiovascular symptoms.
Caused by rapid degranulation of mast cells and basopjils, with systemic release of inflammatory mediators, capillary leak, mucosal oedema and smooth muscle contraction.
May be immunologic (mediated by IgE/immune complexes/complement) or non-immunologic (not mediated by immunoglobulins)

Question 2

Triggers

Answer 2

Food: peanuts, tree nuts, cow’s milk, shellfish and eggs
Insects: rare in children; bees, wasps
Environment: Latex - rare in children (mostly if have had multiple surgeries); important to advise teens on condoms; nb x-rxn with bananas
Drugs: Antibiotics and vaccines

Question 3

Clinical features

Answer 3

Very rapid onset
Flushing, tachycardia, ‘sense of impending doom’
Most likely if mucosal involvement (hives, pruritis. flushing, swelling of lips/tongue/uvula) plus one of:
Respiratory compromise (dyspnoea, wheeze, stridor, hypoxia)
Cardiovascular compromise (hypotension, tachycardia, syncope)
GI involvement: (crampy abdo pain, diarrhoea, vomiting)

Question 4

Management

Answer 4

ABCDE approach
Remove allergen
IM adrenaline
IV hydrocortisone and antihistamine

Question 5

Prevention/on-going management

Answer 5

Allergen avoidance
Referral for allergy testing
Proper training in Epipen use with annual reinforcement (for patient, carers and school)