Anaphylaxis Flashcards
What type of reaction causes Anaphylaxis?
Type 1 Hypersensitivity reaction
What is the pathophysiology of Anaphylaxis?
IgE stimulates Mast cells to release Histamine (aka Mast cell degranulation)
How is the Dx of Anaphylaxis made?
Clinical
What is the key CF that differentiates Anaphylaxis from non-anaphylactic allergic reaction?
Airway / breathing / circulation compromise
(ABC)
What can the CF of Anaphylaxis be divided into?
ABCDE
(emergency examination tings)
What are the AIRWAY CF of Anaphylaxis? (5 things)
- Lip / tongue / pharynx / epiglottis swelling
- Cough
- Swallowing difficulty
- Hoarse voice
- Stridor
What are the BREATHING CF of Anaphylaxis? (9 things)
- Tachypnoea
- Wheezing
- Cough
- Chest tightness
- SOB
- Hypoxia
- Hypercapnia
- Laryngeal oedema
- Bronchospasm
What are the CIRCULATION CF of Anaphylaxis? (10 things)
- Dizziness
- Pallor
- Tachycardia
- Clammy skin
- Drowsiness
- Collapse
- Hypotension
- Prolonged CRT
- Shock
- Arrhythmias / ECG changes
Why do you get Circulation CF in Anaphylaxis? (3 steps)
- Peripheral vasodilation + Increased permeability
- Plasma leakage from circulation
- Decreased intravascular volume
What are the DISABILITY / OTHER CF of Anaphylaxis? (6 things)
- Neuro: Confusion / Anxiety / Collapse
- GI: Abd cramping / DnV
- Other: Feeling of impending death
What are the EXPOSURE CF of Anaphylaxis? (4 things)
- Urticaria (see pic)
- Angioedema (puffy lips / eyes)
- Pruritis (itchy skin)
- Erythema
What can the Differential Dx similar to Anaphylaxis be divided into? (2 things)
- Life threatening DDx
- Non-life threatening DDx
What are the Life threatening DDx that present similarly to Anaphylaxis? (3 things)
- Life-threatening Asthma
- Septic shock
- Hereditary Angioedema
What makes Life threatening Asthma different from Anaphylaxis? (2 things)
- Resp features
- No Skin / CVS / GI features
What makes Septic shock different from Anaphylaxis?
Temp below 36 / above 38
(temp usually normal in anaphylaxis)