Anaphylaxis
Dr. Stella Yiu
Emergency Physician, TOH
LMCC Objectives
History and Physical of allergic reaction pts
Determine urticaria with systemic diseases
Investigations to identify allergens
Manage urticaria and anaphylaxis in ED
1. History and Physical
CDMQ:What can cause allergic reactions?
(5 categories)
Urticaria: triggers
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FlickR creative commons
Drugs
Food allergens
Insects
Physical stressors (cold, exercise)
Respiratory allergy (Pollen)
What systems are involved?
Blood
vessels
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commons
Lungs
GI tract
Soft tissues
© anaphylaxisweb
50% has angioedema
(lips/face/upper airway)
If airway/tongue -> potential airway obstruction
Investigations for allergic reaction/anaphylaxis
No Labs
Maybe skin testing later
2.Acute/chronic + systemic illness
Urticaria
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commons
Systemic illness -> urticaria
Serum sickness
Transfusion reactions
Viral/bacterial infections
Vasculitis
Systemic illness: serum sickness
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Systemic illness: serum sickness
Fever, rash, arthralgia
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Systemic illness: transfusion reactions
Systemic illness: transfusion reactions
Systemic illness: transfusion reactions
Systemic urticaria:Viral/Bacterial infection
Photo credit: Dermatolog Information System
Systemic urticaria:Vasculitis
Associated with
SLE, Sjogren,
Leukemia
Drugs
Systemic unwell:
Arthralgia, fever,
abdo pain,
lymphadenopathy
Photo credit: Dermatology image
atlas
Definition of anaphylaxis
MCQ 5:Who does not have anaphylaxis?
A. Ate peanut butter. Swollen lips and wheezing.
VS normal.
B. Shrimp fest at Red Lobsters. Vomiting and
tight throat.
C. Stung by bee. Low BP.
D. Flu shot. Hives. VS normal.
E. Hay fever, swollen throat, low BP.
Anaphylaxis Definition
> 2 systems: CVS (BP), airway, GI, skin
Skin + airway/BP
BP
3. Manage anaphylaxis
CDMQ: Management steps of patient with
anaphylaxis (8)
Airway (2):
Epinephrine im
Intubate if needed (what indications)
Breathing (1):
Oxygen
B2 agonist (Ventolin)
Bronchodilators
Epinephrine
Circulation (2)
Iv fluids if hypotensive
Iv epinephrine if no better
Fluids
Drugs (3)
Antihistamines
(H1- Benadryl, H2- Ranitidine)
Steroids
Antihistamines
H1: Benadryl
(Diphenhydramine)
H2: Ranitidine
Fluids,
Symptomatic
Discharge instructions
Allergy testing outpatient
Carry Epi-Pen at all times
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Discharge meds
Steroid
-  2nd phase reaction (6-72 hours)
- Prednisone po or solumedrol iv
Continue Antihistamines
LMCC Objectives
History and Physical of allergic reaction pts
Determine urticaria with systemic diseases
Investigations to identify allergens
Manage urticaria and anaphylaxis in ED