Anaphylaxis

Question 1

Define anaphylaxis.

Answer 1

Severe, acute, life-threatening multi system reaction to an allergen

Question 2

What are the early features of anaphylaxis?

Answer 2

Throat/tongue swelling
Hoarseness
Wheeze
Rash

Question 3

What are the late features of anaphylaxis?

Answer 3

Stridor
Shallow breathing
Cyanosis
Confusion (due to hypoxia)
Hypotension

Question 4

Summarise the management of anaphylaxis.

Answer 4

Question 5

What are the ABC symptoms of anaphylaxis?

Answer 5

Airway - swelling, hoarseness, stridor
Breathing - rapid breathing, wheeze, fatigue, cyanosis, SpO2 < 92%, confusion
Circulation - pale, clammy, low BP, faintness, drowsy/coma.

Question 6

What are the doses of adrenaline given to different age groups?

Answer 6

< 6yo = 150mcg
6-12 yrs = 300mcg
> 12yrs and adults = 500mcg

ALL IM.

Question 7

What fluid challenge should you give to adults and children in anaphylaxis?

Answer 7

Adults - 500-1000ml
Child - 20ml/kg

Question 8

What type of fluids may cause anaphylaxis?

Answer 8

Colloid (these contains proteins or starches that attach water)

Question 9

What doses of chlorphenamine and hydrocortisone can be given to adults in allergic reactions?

Answer 9

Chlorphenamine: IM/slow IV 10mg
Hydrocortisone IM/slow IV 200mg

(always 20 times higher dose of hydrocortisone than chlorphenamine except in <6mo)

Question 10

What doses of chlorphenamine and hydrocortisone can be given to children 6-12yo in allergic reactions?

Answer 10

Chlorphenamine: IM/slow IV 5mg
Hydrocortisone IM/slow IV 100mg

(always 20 times higher dose of hydrocortisone than chlorphenamine except in <6mo)

Question 11

What doses of chlorphenamine and hydrocortisone can be given to children <6yo in allergic reactions?

Answer 11

Chlorphenamine: IM/slow IV 2.5mg
Hydrocortisone IM/slow IV 50mg

(always 20 times higher dose of hydrocortisone than chlorphenamine except in <6mo)

Question 12

What is the dose and dilution of adrenaline used in anaphylaxis?

Answer 12

1:1000
0.5mls IM
Repeat after 5min if no response

Also give 200mg hydrocortisone and 10mg chlorphenamine

Question 13

What investigations should be done in anaphylaxis?

Answer 13

Mast cell tryptase - initially thwn 1-2hrs later (should be <1ng/ml but will rise to >100ng/ml in anaphylaxis)

Question 14

How long do you monitor after anaphylaxis?

Answer 14

6-12hrs to monitor for a biphasic reaction

Question 15

What is the management TTA after anaphylaxis?

Answer 15

Prednisolone 40mg for 3-5days
Antihistamine
Discharge with 2 EPIPENS and counsel on how to use these
GP to refer urgently to allergy/immunology clinic for further work up