PECARN STELAR Podcast – Episode 1: Anaphylaxis

The emDOCs.net team is very happy to collaborate with PECARN STELAR (Seattle, Dallas/Texas, and Los Angeles) Node and the Emergency Medical Services for Children Innovation and Improvement Center (EIIC) in presenting high-yield pediatric topics that highlight evidence based medicine with solid research.

Today on we have our two renowned experts, Dr. Ilene Claudius and Dr. Julie Brown, discussing the ins and outs of anaphylaxis.

Anaphylaxis

Show notes by: Mohsen Saidinejad, MD, MS, MBA, on behalf of the PECARN STELAR Node

Background and epidemiology

• Overall incidence of anaphylaxis in children is thought to vary from 1-760 per 10,000 person-years. Overall global incidence of anaphylaxis is 0.04% to 0.81%.¹
• In terms of gender prevalence, boys have higher rate of anaphylaxis than girls in the < 10-year age group. The rates are similar for boys and girls between 10-13 years, and in the > 13 years, the rate of severe anaphylaxis is higher in boys especially for venom or drug induced anaphylaxis.²

What are the criteria for anaphylaxis?

• Referred to as NIAID/FAAN criteria (need one of the following scenarios to be met)
  • An unknown allergen exposure with skin involvement and either respiratory involvement or hypotension.
  • A likely allergen exposure and 2 for the following 4 criteria
    • Skin involvement, persistent GI symptoms, respiratory compromise, or hypotension
  • A known allergen exposure and hypotension

*Note: These criteria are not the criteria for when epinephrine should be used.

What are some considerations for identifying anaphylaxis?

• No specific signs or symptoms have been identified that are unique to anaphylaxis.
• No specific diagnostic tests exist that can help make a timely diagnosis of anaphylaxis.
• Timing and type of exposure is very important.
  • A known prior exposure to same allergen (especially food) is important, although this can be a challenge to recognize.
  • First allergen exposure may be mild or even unrecognizable.
• Anaphylaxis occurs over more than one exposure.  The first exposure “primes” the child for more severe reaction in subsequent exposures.

Epinephrine uses in anaphylaxis.

• Epinephrine may be indicated even if none of the above definitions of anaphylaxis have been met. For example, a child who has:
  • One severe criterion (e.g. respiratory compromise or hypotension) or
  • Two mild/moderate criteria (e.g. rash/hives and GI symptoms)
  • Definite exposure to a known allergen, even if only rash/hives, (e.g. a child who has peanut allergies and a known recent peanut ingestion, who presents to the ED with full body hives) – so no need to wait for additional criteria of anaphylaxis to be met.³
    • Seattle Children’s anaphylaxis pathway

 Management approach to a child with anaphylaxis

• Epinephrine is the only medication that has shown to alter the course of anaphylaxis.
  • It is the mainstay of anaphylaxis treatment and is given first. If anaphylaxis is suspected, use of other medications and reassessment before epinephrine is given is NOT
  • IM epinephrine is preferred, due to great response, can avoid IV placement for other resuscitation needs, unless severe anaphylaxis with hypotension.
• Supine positioning because vasodilation can compromise venous return to the heart. This is also important while giving epinephrine, to optimize its circulation.
  • Except when respiratory compromise makes breathing difficult in supine position.
• Oxygen should be used as needed for children who are hypoxic.
• Antihistamines improve skin and upper respiratory symptome, but do not alter anaphylaxis.
  • An H1 receptor blocker should be used with an H2 receptor blocker as ~15% of mast cells are H2 receptor type.
  • Use of a less sedating antihistamine (e.g. cetirizine) is recommended.
• Steroids in anaphylaxis are controversial.
  • Do not prevent persistent symptoms or biphasic reaction.
  • No benefit in short term symptoms
  • May provide benefit in children with atopy history (e.g. asthma), those who require hospitalization, and those who have late onset symptom development.

Other considerations:

• IV epinephrine may be used for anaphylaxis as a continuous drip for those who are not responding to at least 3 doses of IM epinephrine.
• IV epinephrine bolus dose is NEVER recommended as anaphylaxis and should be considered as part of the cardiac resuscitation pathway instead.
• Other modalities (sublingual or intranasal epinephrine) are not yet FDA approved.

What are admission criteria for anaphylaxis?

• Generally, persistence of symptoms predict admission need. The number of epinephrine doses do not necessarily dictate admission need, but if subsequent doses were given within greater time intervals, it would suggest ongoing symptoms.
• Seattle Children’s anaphylaxis pathway uses a score of ≥5 as admission criteria.

What are ED discharge considerations for anaphylaxis?

• Over the years, observation and admission rates have decreased, similarly to the case with croup. A sub-set of children can be identified as low risk and can be discharged.  Tim Dribin, MD has done some work⁴in this area.
• If antihistamines were given in the ED, PRN doses may be prescribed for home use.
• No home dose of steroids are needed.
• Every child with anaphylaxis presentation needs an epipen “in hand” and always.
• An allergist consultation is needed for any anaphylaxis if the child has not been evaluated.

References:

1. Wang Y, Allen KJ, Suaini NHA, McWilliam V, Peters RL, Koplin JJ. The global incidence and prevalence of anaphylaxis in children in the general population: A systematic review. Allergy. 2019 Jun;74(6):1063-1080. doi: 10.1111/all.13732. Epub 2019 Mar 6. PMID: 30688375.
2. Tarczoń I, Cichocka-Jarosz E, Knapp A, Kwinta P. The 2020 update on anaphylaxis in paediatric population. Postepy Dermatol Alergol. 2022 Feb;39(1):13-19. doi: 10.5114/ada.2021.103327. Epub 2021 Feb 6. PMID: 35369644.
3. Pediatric anaphylaxis pathway. Seattle Children’s Hospital. Found at: https://www.seattlechildrens.org/globalassets/documents/healthcare-professionals/clinical-standard-work/anaphylaxis_org_pathway.pdf. Accessed March 20, 2024
4. Dribin TE, Michelson KA, Monuteaux MC, Stack AM, Farbman KS, Schneider LC, Neuman MI. Identification of children with anaphylaxis at low risk of receiving acute inpatient therapies. PLoS One. 2019 Feb 7;14(2):e0211949. doi: 10.1371/journal.pone.0211949. PMID: 30730977