Anaphylaxis is caused by a severe type 1 hypersensitivity reaction. Immunoglobulin E (IgE) stimulates mast cells to produce histamine and other pro-inflammatory chemicals. This called mast cell degranulation.
What differentiates anaphylaxis from non-anaphylactic allergic reaction?
Compromised airway, breathing and circulation.
Anaphylaxis usually presents with a history of exposure to allergen or can be idiopathic.
What allergic symptoms can anaphylaxis present with?
Urticaria
Itching
Angio-oedema - swelling around lips and eyes
Abdominal pain
What additional symptoms can indicate anaphylaxis?
Shortness of breath
Wheeze
Swelling of larynx - stridor
Tachycardia
Light headedness
Collapse
Principles of management of anaphylaxis (A-E)
A - Secure the airway
B - Provide oxygen if required, salbutamol can help with wheeze
C - IV bolus of fluids
D - Lie patient flat to increase cerebral perfusion
E - Look for flushing, urticaria and angio-oedema
Which three medications do you give in anaphylaxis?
IM Adrenaline - repeat after 5 mins if required
2. Steroids - IV Hydrocortisone
3. Antihistamines - Chlorphenamine or cetirizine
How can anaphylaxis be confirmed?
Measuring serum mast cell tryptase within 6 hours of the event.
