Anaphylaxis - Paediatric

Key Points:

Anaphylaxis is a severe allergic response manifest by typical skin features and involvement of one or more of the:

Respiratory system
Cardiovascular system
Gastrointestinal system
OR
Any acute onset episode of bronchospasm or hypotension or upper airway obstruction where anaphylaxis is considered a possibility. Serum tryptase levels in consultation with a paediatric allergy specialist can be helpful when the diagnosis of anaphylaxis is uncertain

Clinical

Signs and symptoms of anaphylaxis for each system includes:

Skin features (absent in approximately 20%): Urticaria, erythema, flushing or angioedema
Respiratory (More common than cardiovascular symptoms in children): Itchy mouth or throat, tongue or throat swelling, rhinitis,cough, wheeze
Cardiovascular: Tachycardia, pallor, light-headedness, lethargy, pallor, hypotension (late sign)
Gastrointestinal (Severe and persistent symptoms): Vomiting, abdominal pain, diarrhoea

It is important to identify the risk factors for fatal anaphylaxis from a thorough history and plan to reduce these risks in consultation with the family:

Not lying child supine
Delay to administration of adrenaline
Poorly controlled asthma
Adolescence
Allergy to nut or shellfish

Treatment

Assess ABC
High flow oxygen
IM Adrenaline (flow diagram for dose)
REPEAT IM Adrenaline @ 3-5 mins if required
Nebulised Adrenaline if airway obstruction
Treat ↓ BP with 20ml/kg fluid bolus
Consider Salbutamol nebs if wheeze
Antihistamines given for itch (not "collapse")
Early anaesthetic involvement if airway obstruction
Early ENT involvement if possibility surgical airway required

Management approach

Adrenaline dosing
Age (yrs)	Wt	Vol. Adrenaline 1 : 1000	Adrenaline autoinjectors
<1	5-10	0.05 - 0.1 mL
1-2	10	0.1 mL	10-20 kg (1-5yrs) = 0.15 mg (green label) device
2-3	15	0.15 mL
4-6	20	0.2 mL
7-10	30	0.3 mL	>20kg (>5y) = 0.3mg (yellow label) device
10-12	40	0.4 mL
>12 & adult	>50	0.5 mL

Discharge criteria:

Patients should be observed for 6 hours following administration of adrenaline. The child must be symptom free at the time of discharge
Fill in the allergy clinic referral form
Prescribe 2 epipens (junior <30kg, or epipen >30kg)
Contact allergy CNS during working hours for education. Afterhours – educate using epipen trainer found in CNF office
Give anaphylaxis action plan

Admit

The child should be admitted overnight if:

Two or more adrenaline injections were required
Lives a significant distance from medical services
Poorly controlled asthma
Ongoing symptoms