Anaphylaxis Flashcards
What type of reaction is anaphylaxis?
Type 1 hypersensitivity reaction
What type of immunoglobulins are involved in anaphylaxis?
IgE immunoglobulins.
What distinguishes anaphylaxis from other type 1 hypersensitivity reactions?
3 Things:
- Compromised airway, breathing and circulation.
How does anaphylaxis present?
Exposure to allergen Rapid onset of allergic symptoms: Angioedema Swelling of lips and eyes Rash Urticaria Abdominal pain Dyspnoea Wheeze Stridor (swelling of larynx) Tachycardia Presyncope Collapse
How does IgE cause anaphylaxis?
IgE immunoglobulins cause mast cell degranulation of histamine amongst other things.
How is anaphylaxis managed?
-ABCDE Airways - maintain patent airway Breathing - give oxygen Circulation - ive IV fluid D - lie patient flat Exposure - look at skin
- Ask for help
- IM Adrenaline
What are usually the first changes seen in anaphylaxis?
Skin chances (BUT they’re absent in 10-20% of people):
Urticaria
Angioedema
What is a marker of anaphylaxis?
Mast cell tryptase.
Is released during mast cell degranulation.
Should be measured no longer than 6 hours after anaphylaxis reaction
It confirms the diagnosis.
NOT part of initial treatment.
What other medications can be given in anaphylaxis treatment?
INITIAL management:
IM Adrenaline
NOT part of initial management:
Antihistamines (chlorphenamine or cetirizine)
Steroids (IV hydrocortisone)
Nebulised salbutamol (Not as useful for airways as adrenaline)
What should you look out for after an anaphylaxis shock reaction?
A second reaction (biphasic reaction)
When can more IM adrenaline be given?
Can be released after 5 mins if needed
What are the side effects of adrenaline?
Nausea Vomiting Tachycardia Headache Anxiety
How does adrenaline work?
Causes vasoconstriction and restores blood pressure
How does chlorphenamine work?
(Anti-histamine)
Relaxes bronchial smooth muscle blocks the action of histamine on H1 receptors
Reduces vascular permeability
How does hydrocortisone work?
Dampens down inflammation
