Emergency: Anaphylaxis

Question 1

Describe anaphylaxis

Answer 1

A severe, life threatening, generalised or systemic hypersensitivity reaction. Sudden in onset, progresses rapidly, with life threatening breathing, airway and/or circulatory problem

Question 2

In children, 85% of anaphylaxis is due to…

Answer 2

Food allergy

Most are IgE mediated reactions with significant respiratory or cardiovascular compromise

Question 3

Other than food allergy what are some other causes of anaphylaxis?

Answer 3

Insect stings
Drugs
Latex 
Exercise 
Inhaled allergens 
Idiopathic

Question 4

Among what age group does the majority of fatal anaphylaxis occur?

Answer 4

Adolescents with allergy to nuts

Question 5

What are some risk factors for fatal outcome?

Answer 5

Adolescent age group
Coexistent asthma
Nut allergy

Question 6

What is involved in the acute management?

Answer 6

ABCDE

Early administration of IM adrenaline

Question 7

In terms of the airway, what symptoms/signs are seen?

Answer 7

Stridor
Swelling
Hoarseness

Question 8

Describe stridor

Answer 8

A loud, harsh, high pitched respiratory sound
May start low pitched ‘croaking’ then progress to high pitched ‘crowing’ on more vigorous respiration
Usually heard on inspiration due to partial obstruction of the airway (usually extrathoracic - in trachea, larynx or pharynx)

Question 9

In terms of breathing, what symptoms/signs may be seen?

Answer 9

Tachypnoea
Wheeze
Cyanosis
SpO2 < 92%

Question 10

What symptoms/signs are seen with regards to circulation?

Answer 10

Pale, clammy, hypotension, drowsy, dizziness, coma

Question 11

What skin/ mucosal signs can be seen?

Answer 11

Urticaria
Angioedema
- usually but not always present

Question 12

Most paediatric anaphylaxis occurs in children under what age?

Answer 12

5 years

Question 13

The acute management of anaphylaxis relies on early administration of what?

Answer 13

Adrenaline

Question 14

What strength adrenaline should be used?

Answer 14

1:1000

Question 15

If the patient is hypotensive, how should they be positioned?

Answer 15

Supine with legs elevated

Question 16

If breathing is difficult how should patient be positioned?

Answer 16

Sat upright

Question 17

In addition to adrenaline, what other treatment can be given?

Answer 17

High flow oxygen 
IV fluid 20ml/kg cystalloids 
Chlorphenamine IM or slow IV
Hydrocortisone IM or slow IV 
Consider salbutamol if wheeze

Question 18

How should patient be monitored?

Answer 18

Pulse oximetry
ECG
BP

Question 19

What does long term management involve?

Answer 19

Strategies and training for allergy avoidance
Written management plan with instructions for treatment of allergic reactions
Provision of adrenaline auto-injectors

In some cases allergen immunotherapy may be effective in preventing future episodes

Question 20

What type of hypersensitivity reaction is anaphylaxis?

Answer 20

Type 1 (immediate)

Question 21

Does adrenaline treat all of the most dangerous symptoms of anaphylaxis?

Answer 21

Yes - it treats throat swelling, difficulty breathing and hypotension

Also helps alleviate itching, rash, swelling, GI and urinary symptoms

Question 22

Peak plasma concentration of adrenaline occurs how long after administration?

Answer 22

8 +/- 2 minutes
Respiratory or cardiac arrest can occur as early as 6 minutes for food triggered reactions and 4 for venom triggered (median times = 30 and 15 respectively)

Question 23

How does adrenaline work? Ie on what receptors

Answer 23

Alpha receptors to cause peripheral vasoconstriction

Beta receptors to cause bronchodilation and inotropic effects e.g increasing CO

Question 24

What dose of adrenaline should be given if aged less than 6 months?

Answer 24

0.15ml (150mcg)

Question 25

What does of adrenaline should be given if aged 6 months to 6 years?

Answer 25

0.15mL (150mcg)

Question 26

What dose of adrenaline should be given if aged 6-12 years?

Answer 26

0.3mL (300mcg)

Question 27

What is the adolescent/ adult dose of adrenaline?

Answer 27

0.5mL (500mcg)

Question 28

If there is no improvement after adrenaline dose, what should be done?

Answer 28

Repeat after 5 mins

Question 29

If bronchospasm is a feature what should be given?

Answer 29

Nebulised salbutamol 2.5mg every 15 minutes as required If child >30kg give 5mg

Question 30

What are some differentials for anaphylaxis?

Answer 30

Asthma Septic shock Panic attack

Question 31

What is the most common food to cause anaphylaxis?

Answer 31

Peanuts

Question 32

What are the most common drugs to cause anaphylaxis in children?

Answer 32

Vaccines | Penicillins

Question 33

Who should influenza vaccines not be given to?

Answer 33

Children with an egg allergy

Question 34

Do foods tend to cause respiratory and airway symptoms or cardiovascular collapse?

Answer 34

Respiratory and airway Injections and stings - CVS collapse

Question 35

All children with suspected anaphylaxis should be referred for...

Answer 35

Allergy testing

Question 36

What foods are the most common cause of anaphylaxis in children?

Answer 36

``` Peanut Cashew Other nuts Milk Eggs Seafood Vegetables/fruit Soya milk Rice Wheat Sesame ```

Question 37

What are the absolute indicators for at least one adrenaline auto injector?

Answer 37

Allergy to high risk foods - peanuts, tree nuts, shellfish Previous anaphylaxis to other food or latex Idiopathic anaphylaxis Unstable or moderate to severe persistent asthma with food allergy

Question 38

What are suggested indications for prescription of a second adrenaline auto injector?

Answer 38

Unstable or moderate to severe persistent asthma with food allergy Coexisting mast cell disease Lack of rapid access to medical assistance e.g geographical isolation Previous requirement for more than one dose of adrenaline prior to reaching hospital Previous near fatal anaphylaxis