A lecture for EM residents. Texts are taken mainly from Tintinalli's Emergency Medicine: A Comprehensive Guide, 9th ed

1. TINTINALLI’S HOUR:
ALLERGY AND
ANAPHYLAXIS
Dr. Jo Anne Ramos
Medical Officer III
Department of Emergency Medicine
BATAAN GENERAL HOSPITAL AND
MEDICAL CENTER
D E PA R T M E N T O F E M E R G E N C Y M E D I C I N E

2. TOPIC OUTLINE
Introduction​
Pathophysiology
Clinical Features
Treatment
Disposition and Follow-up
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3. Introduction
Anaphylaxis is a common medical emergency and a life-
threatening acute hypersensitivity reaction.
It can be defined as a rapidly evolving, generalized,
multi-system, allergic reaction.
Without treatment, anaphylaxis is often fatal due to its
rapid progression to respiratory collapse.
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4. INTRODUCTION
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• Food represents the most common trigger for anaphylaxis
admissions to hospital, but not the most common cause of
anaphylaxis-related fatalities.
• The lifetime individual risk of anaphylaxis is estimated to be 1%
to 3%, but the prevalence of anaphylaxis may be increasing.
Turner PJ, Campbell DE, Motosue MS, Campbell RL. Global Trends in Anaphylaxis Epidemiology and Clinical Implications. J Allergy Clin Immunol Pract. 2020;8(4):1169-
1176. doi:10.1016/j.jaip.2019.11.027

5. 2021 PATHOPHYSIOLOGY
ANAPHYL AX I S 5

6. CLINICAL CRITERIA
World Allergy Organization
Anaphylaxis Guidance 2020
Cardona V, Ansotegui IJ, Ebisawa M, et al. World allergy organization anaphylaxis guidance 2020. World Allergy Organ J. 2020;13(10):100472. Published
2020 Oct 30. doi:10.1016/j.waojou.2020.100472

7. THE CLASSIC
PRESENTATION OF
ANAPHYLAXIS BEGINS
WITH PRURITUS,
CUTANEOUS
FLUSHING, AND
URTICARIA.
CLINICAL FEATURES
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THESE SYMPTOMS ARE
FOLLOWED BY A SENSE
OF FULLNESS IN THE
THROAT, ANXIETY, A
SENSATION OF CHEST
TIGHTNESS, SHORTNESS
OF BREATH, AND
LIGHTHEADEDNESS.
A COMPLAINT OF A
“LUMP IN THE THROAT”
AND HOARSENESS
HERALDS LIFE-
THREATENING
LARYNGEAL EDEMA IN A
PATIENT WITH
SYMPTOMS OF
ANAPHYLAXIS.

8. USUALLY
OCCURS:
Within 60 minutes
after exposure
THE FASTER
THE ONSET OF
SYMPTOMS
The more the
severe the reaction
HALF OF THE
FATALITIES
Occur within the
FIRST HOUR
SECOND
PHASE
MEDIATOR
RELEASE
Peaks: 8-11 hours
Clinical
manifestation: 3-4
hours (after
cessation of initial
manifestation)
BIPHASIC
PHENOMENON
Due to late-phase
allergic reaction of
newly generated
cysteinyl
leukotrienes
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DIAGNOSIS

9. • The diagnosis of
anaphylaxis is CLINICAL.
• Consider, if there are
involvement of 2 or more
body systems is observed
with or without hypotension
or airway compromise.
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Laboratory investigations are of minimal utility
and should be limited in the ED setting.

10. DIFFERENTIAL DIAGNOSIS
Most common
anaphylaxis imitator
VASOVAGAL REACTION:
- Characterized by hypotension, pallor,
bradycardia, diaphoresis, and weakness,
and sometimes LOC.​
• MYOCARDIAL ISCHEMIA
• DYSRHYTHMIA
• SEVERE ACUTE ASTHMA
• SEIZURE
• EPIGLOTTITIS
• HEREDITARY ANGIOEDEMA
• FOREIGN BODY AIRWAY
OBSTRUCTION
• CARCINOID
• MASTOCYTOSIS
• VOCAL CORD DYSFUNCTION
• NON-IgE MEDIATED DRUG
REACTIONS
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11. TREATMENT
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12. AIRWAY
Securing the airway
is the priority in
anaphylaxis.
OXYGENATION
Provide
supplemental
oxygen to maintain
sats at >90%
DECONTAMINATION
Termination of
exposure
EPINEPHRINE
Treatment of choice
for anaphylaxis
IV CRYSTALLOIDS
Responds well to
fluid resuscitation.
It should be
administered
concurrently with
Epi
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FIRST LINE THERAPY

13. Dodd A, Hughes A, Sargant N, Whyte AF, Soar J, Turner PJ. Evidence update
for the treatment of anaphylaxis [published online ahead of print, 2021 Apr
23]. Resuscitation. 2021;163:86-96. doi:10.1016/j.resuscitation.2021.04.010
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14. SECOND LINE
THERAPY
• CORTICOSTEROIDS
• ANTIHISTAMINE
• INHALED BRONCHODILATORS
• VASOPRESSORS
• GLUCAGON
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15. CORTICOSTEROIDS
Methylprednisolone: 80-125mg/IV (adults)
1-2mg/kg (children)
Hydrocortisone: 250-500mg/IV (adult)
5-10mg/kg (children)
Prednisone: 40-60 mg PO daily (adult; 3-5 days)
1-2 mg/kg daily (children)
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17. ANITHISTAMINES
• H1 antihistamine
• Diphenhydramine 25-
50mg/IV slowly or IM
• H2 antihistamines
• Ranitidine 50mg/IV
• Cimetidine 300mg/IV
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19. INHALED
BRONCHODILATORS
Salbutamol
• Neb (2.5-5mg, adults; 1.25-
2.5mg, pedia)
• MDI (4-6 puffs with holding
chamber)
• Repeated every 20 minutes
PRN
• Continuous neb: 5-10mg/h,
adults; 3-5mg/h, pedia
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20. INHALED
BRONCHODILATORS
Ipratropium Br
• Neb 250-500mcg, adults; 125-
250mcg, pedia
• 4-6 puffs with holding
chamber
• Repeated every 20 minutes
PRN
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21. 21

22. MAGNESIUM SULFATE
• IV bronchodilator
• Mg sulfate: 2g/ IV over 20 mins
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23. 23
Among children with refractory acute
asthma in the emergency department,
nebulized magnesium with albuterol,
compared with placebo with albuterol, did
not significantly decrease the
hospitalization rate for asthma within 24
hours. The findings do not support use of
nebulized magnesium with albuterol among
children with refractory acute asthma.

24. GLUCAGON
• For patients taking β blockers
with hypotension, refractory to
fluids and Epi
• Adult: 1 mg IV every 5 min to
effect then 5-15 mcg/min
infusion
• Pedia: 50mcg/kg IV every 5
mins
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25. DISPOSITION
• All unstable patients with
anaphylaxis refractory to
treatment or in whom
airway interventions were
required should be
admitted to the intensive
care unit.
• While patients who
receive epinephrine IM
should be observed in the
ED
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26. DISCHARGED PATIENTS
PLAN
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27. ALLERGIES AND
ANGIOEDEMA

28. URTICARIA
Also known as hives, is a
cutaneous reaction marked by
acute onset of pruritic, erythemic
wheals of varying size
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Treatment is generally supportive
and symptomatic.
H1 blckers with or without
corticosteroids are usually
prescribed
Epinephrine can be considered in
severe or refractory cases
Cold compress may be soothing
to affected areas.
Referral to an allergy specialist is
indicated for severee, recurrent,
or refractory case..

29. ANGIOEDEMA
A similar reaction as urticaria but
with deeper involvement
characterized by edema formation
in the dermis, generally involving
the face and neck and distal
extremities.
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Angioedema of the tongue, lips,
and face has the potential for
airway obstruction.
Co mmon trigger: ACE inhibitors
Drugs used to treat allergic
reactions are not beneficial
because ACE inhibitor-induced
angioedema is not medicated by
IgE..

30. Icatibant (bradykinin-2-antagonist)
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TREATMENT

31. HEREDITARY
ANGIOEDEMA
It is a rare autosomal dominant
disorder due to deficiency in C1
esterase inhibitor, either low levels
(type I) or a dysfunctional enzyme
(type II).
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Prophylaxis of acute attacks is
possible with attenuated
androgens, such as Stanozolol
2mg/tab PO TID or Danazol
200mg/tab PO TID
Refer to appropriate specialist.
Attacks can last hours to 1-2 days.
Minor trauma often precipitates
an acute episode.
Attacks can last hours to 1-2 days.
Minor trauma often precipitates
an acute episode.

32. HYPERSENSITIVITY
REACTIONS TO
INGESTED FOODS ARE
CAUSED BY MAST
CELLS LINING THE GI
TRACT TO INGESTED
FOOD PROTEINS.
FOOD ALLERGY REACTIONS
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HYPERSENSITIVITY
REACTIONS TO
INGESTED FOODS ARE
CAUSED BY MAST
CELLS LINING THE GI
TRACT TO INGESTED
FOOD PROTEINS.
DAIRY PRODUCTS,
EGGS, NUTS,
SHELLFISH ARE THE
MOST COMMONLY
IMPLICATED FOODS.

33. Mammalian meat
allergy
Galactose-alpha-1,3-galactose allergy: IgE-mediated
allergic reaction to ingestion of red meat containing
mammalian oligosaccharide epitope alpha-gal.
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The onset is about 4 hours (3-8 hours) after eating
meat, manifested by urticaria, angioedema,
gastroenteritis, or anaphylaxis.
Diagnosis is confirmed by blood testing with a positive
reaction to specific IgE alpha-gal antibodies.

34. ALLERGIC DRUG
REACTIONS

35. Adverse reaction to drugs are common; however,
true hypersensitivity reactions account for <10% of
these occurrences, with the majority anaphylaxis
from IgE-mediated drug reactions.
Penicillin is the drug most commonly implicated in eliciting
true allergic reactions and accounts for approximately 90% of
all reported allergic drug reactions and about 75% of fatal
anaphylactic drug reactions.
Fatal reactions can occur without a prior allergic history;
<25% of patients who die of penicillin-induced anaphylaxis
exhibited allergic reactions during previous treatment with the
drug.

36. DIAGNOSIS IS DETERMINED BY A CAREFUL
HISTORY.
TREATMENT IS SUPPORTIVE, WITH ORAL
OR PARENTERAL ANTIHISTAMINES AND
CORTICOSTEROIDS.
DRUG CESSATION IS IMPORTANT, BUT
REACTIONS CAN CONTINUE.
REFERRAL TO AN ALLERGY SPECIALIST IS
INDICATED FOR SEVERE REACTIONS.

37. THANK YOU BEA!
Top 5 Miss Universe 2021
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