Anaphylaxis

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full PCH Emergency Department disclaimer.

Aim 

To guide PCH ED staff with the assessment and management of anaphylaxis presenting to the Emergency Department.

Background 

Anaphylaxis is an IgE mediated potentially life‐threatening severe allergic reaction, which may progress to shock and severe airway compromise.
The most common causes of anaphylaxis in children include:
  • Foods: Peanut, tree nut, egg, cow’s milk, soy, wheat, sesame seeds, fish and seafood.
  • Insect stings and bites: Bees, wasps, hornets, jack jumper ants, fire ants.
  • Latex
  • Drugs: Penicillin, NSAIDS, Aspirin, anaesthetic agents, radiographic contrast media.
  • Exercise, also in combination with certain foods, heat, cold, pressure.

Risk factors

  • Asthma

Assessment

  • Asthma: asthmatics are more likely to have more severe respiratory problems during anaphylaxis. In particular with food allergy (especially to peanuts and tree nuts).
  • The severity of past allergic reactions does not reliably predict the severity of future reactions.

Download the Anaphylaxis flowchart (PDF 114kb)

Examination

Symptoms of allergic reactions are categorised as mild, moderate or as anaphylaxis (= severe):

Clinical features

Mild to moderate allergic reaction
  • swelling of the lips, face, eyes
  • tingling of the mouth
  • hives or welts
  • abdominal pain (abdominal pain and vomiting can be a sign of anaphylaxis in insect allergy)
  • difficulty breathing
  • tongue swelling.
Anaphylaxis (only one feature may present)
  • swelling/tightness in the throat
  • difficulty speaking/hoarse voice
  • wheeze or persistent cough
  • persistent dizziness
  • pallor and floppiness (in young children)
  • abdominal pain and vomiting in insect allergy.

Management

  • Ensure allergen is removed
  • Assess ABC and take blood pressure
  • Give high flow oxygen
  • Lay the patient flat, if there is respiratory distress then the patient can sit upright
  • Do not allow the patient to stand or walk
  • Record patient’s T,P,R, BP, SpO2 (Full EDOES if clinically indicated)
  • Full neurological observations (FNO) as clinically indicated
  • Document chest auscultation and perfusion
  • Document and report presence of urticarial rash, itching of lips, mouth or throat, facial swelling, difficulty breathing, wheezing, coughing, chest tightness, stridor, circulatory shock (ie: sluggish capillary refill, hypotension, weak pulses), nausea and vomiting.

Initial management

Anaphylaxis

  • Give intramuscular (IM) Adrenaline (1:1000 strength = 1 mg/mL)
    • Dose: 0.01mg/kg
    • Maximum dose: 0.5mg
  • Continuous cardiac monitoring, pulse oximetry
  • Document: P, R, BP, SpO2 15 to 30 minutely until stable
    • Observe closely and report worsening symptoms.

Shock

  • Insert two large IV cannulae and give 20mL/kg of 0.9% saline bolus. Repeat as necessary.
  • Consider starting an Adrenaline infusion if the patient remains hypotensive after 40mL/kg of 0.9% saline
  • PCCU referral.

Upper airway obstruction

  • Give 5mL of nebulised Adrenaline (strength 1:1000 - 1mg/1mL)
  • Consider need for intubation and prepare equipment
  • Consider Adrenaline infusion, PCCU referral
  • Continuous cardiac monitoring, pulse oximetry
  • Document: P, R, BP, SpO2 five to 15 minutely until stable
  • Observe closely and report worsening symptoms.

Persistent wheeze

  • Give Salbutamol via spacer:
    • 6 puffs <6 years
    • 12 puffs ≥6 years
  • Consider Adrenaline infusion
  • PCCU referral.

Further management

  • Consider antihistamines for itch and urticaria 0.15mg/kg Loratadine (maximum 10mg)
  • Consider prescribing a two day course of Prednisolone (1mg/kg) to reduce the risk of symptom recurrence after a severe reaction
  • Prescribe two Epipens (autoinjector) to all patients > 10kg
    • Use PBS script pad and get PBS authorisation
    • Contact number: 1800 888 333 (available 24 hours)
  • Educate parents on the use of the Epipen and provide ASCIA Action Plans for Anaphylaxis

Admission criteria

  • If the child is hypotensive or hypoxic admit to the ward, consider PCCU referral
  • If the child is not hypotensive or hypoxic admit to the ED Short Stay ward for a minimum of 4 hours post adrenaline
  • Do not discharge overnight

Observe for a longer period of time if there is:

  • History of asthma
  • Protracted anaphylaxis
  • > 1 dose of adrenaline required
  • Other concomitant illness

Referrals and follow-up

  • Refer to a specialist allergy clinic – either a Private Immunologist or Immunology Outpatient Clinic at PCH

Bibliography

  1. AMH Children’s Dosing Companion (2015) Australian Medicines Handbook Pty Ltd
  2. Australian Injectable Drugs Handbook (AIDH) - 7th Edition 2017
  3. American Academy of Allergy, Asthma and Immunology (AAAAI) anaphylaxis parameter
  4. ASCIA World Allergy Organisation (WAO) anaphylaxis guidelines

  • difficulty breathing
  • tongue swelling
  • difficulty breathing
  • tongue swelling

Reviewer/Team: Meredith Borland (ED Director), Dennis Chow (ED Consultant), Deirdre Speldewinde (ED Consultant), Gabrielle Anstey (ED CNS), Craig Hasler (ED CNM), Richard Loh (HoD Immunology)
Last reviewed: Jan 2018


Review date: Jan 2019
Endorsed by:

Director, Emergency Department Date:  Jan 2018


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