Anaphylaxis

Question 1

An 18 month old boy is brought to the ED with peri-orbital swelling, noisy breathing, drooling, and a raised, erythematous rash within 5 minutes of eating cashew nuts for the first time. His mother has noted that his voice is getting hoarse.

Answer 1

Impression
Anaphylaxis and upper airway obstruction given temporal relationship to eating nuts (common food allergen) and skin + resp sx in keeping with clinical syndrome. This is a medical emergency demanding emergent treatment and management to stabilise the patient.

Unlikely to be infective such as croup/pneumonia, or FB, also unlikely renal cause such as nephrotic syndrome given acute nature of the presentation.
Otherwise
- asthma exacerbation (unlikely given age of patient)

Goals
- Call for senior help and initiate emergency treatment utilise A to E assessment approach, administering IM adrenaline and gaining IV access for fluid resuscitation
- stabilisation and then ongoing monitoring for relapse of sx, or for delayed anaphylactic response

Question 2

Anaphylaxis - Assessment

Answer 2

Assessment
- call for senior help, paediatrics
- begin drawing up medications for IV administration of adrenaline/nebulised adrenaline
- remove allergen if still present, keep patient lying down do not allow to stand or walk
- Administer 0.01mL/kg of 1:1000 adrenaline IM immediately (according to rCH anaphylaxis guidelines), repeat after. minutes if no improvement and no IV access as yet

A - patency, degree of stridor; auscultate upper airway, AVPU; low threshold for intubation/surgical airway, consider nebulised adrenaline
B - wheeze, cough, WOB, RR/SP02 monitoring. administer supplemental 02 via bag/valve, consider PPV, consider salbutamol for ?asthma, CXR for DDx
C - achieve IV access, ideally 2 large bore. initial bloods (VBG, serum tryptase <4 hrs, FBC, UEC, LFT), Begin IV infusion of adrenaline if clinical indicated under advice of senior clinician, 20ml/kg IV bolus infusions of 0.9% NS. Consider administering antihistamines, mainly for symptomatic treatment of pruritus
D - AVPU

Question 3

Anaphylaxis - History

Answer 3

History
- take history collaterally and concurrently:
- Sx: wheeze, stridor, WOB, sudden onset, swelling, oedema, skin rash (urticarial, evolving/changing)
- HPI: cashew nuts, previous exposure? other allergies, family history
- paeds hx: development, pregnancy, birth, immunisations,
- PMHx, known asthma diagnosis? any medications?

Question 4

Anaphylaxis - Examination

Answer 4

Examination
- as per A to E
- full cardiorespiratory examination

Question 5

Anaphylaxis - Investigations

Answer 5

Investigations
as per A to E
- serum tryptase level to confirm anaphylaxis
- FBC for eosinophilia

later
- patch testing, total IgE level

Question 6

Anaphylaxis - Management

Answer 6

Management
- initial stabilisation as per A to E assessment
- Consider PICU/NETS retrieval if non-remitting or not responding to treatment

Then
- observation for at least 4 hours id stabilised postadrenaline
- admission if not, regular obs for relapse

Supportive
- parental education: to avoid allergen,
- anaphylaxis management plan; epipen and education on use
- referral to paediatrician or allergen specialist for review
- any relevant asthma control
- update medical record highlighting allergens to avoid