Anaphylaxis Flashcards
Define Anaphylaxis?
Acute life-threatening multisystem syndrome caused by sudden release of mast cell and basophil-deviated mediators into the circulation
What is the aetiology of anaphylaxis?
Immunogenic - IgE-mediated or immune complex/complement-mediated
Non-Immunogenic - mast cell or basophil degranulation without the involvement of antibodies
What is the pathophysiology of Anaphylaxis?
Inflammatory mediators such as histamine are released leading to bronchospasm, increased capillary permeability and reduce vascular tone
This leads to tissue oedema
What are the common allergens that cause Anaphylaxis?
Drugs (e.g. Penicllin)
Latex
Peanuts
Shellfish
What is the other common way in which Anaphylaxis can be caused?
It can be caused by the repeat administration of blood products in a patient with selective IgA deficiency (due to the formation of anti-IgA antibodies)
What is the epidemiology of Anaphylaxis?
Common
What are the presenting symptoms of anaphylaxis?
Wheeze Shortness of breath and sense of choking Swelling of lips and face Pruritus Rash
What is Pruritus?
Also known as itch and is defined as an unpleasant sensation of the skin that provokes the urge to scratch
What are the signs of anaphylaxis?
Tachypnoea Wheeze Cyanosis Swollen upper airways and eyes Rhinitis Conjuctival Infection Urticarial Rash Hypotension Tachycardia
What are the appropriate investigations for anaphylaxis?
CLINICAL diagnosis
Serum Tryptase, histamine levels or urinary metabolites of histamine may help support the clinical diagnosis
What should you do following an attack?
Allergen skin testing - identifies allergen
IgE immunoassays - identifies food-specific IgE in the serum
What is the immediate management for anaphylaxis?
ABCDE Airways Breathing Circulation Disability Exposure
What is the long-term plan for anaphylaxis?
High flow oxygen IM adrenaline Chlorpheniramine (antihisamine) Hydrocortisone If continue respiratory deterioration, may require bronchodilator therapy Monitor pulse oximetry, ECG and BP
What are the possible complications of anaphylaxis?
SHOCK
Organ damage can result from shock
What is the prognosis for patients with anaphylaxis?
Good with prompt treatment
