What is anaphylaxis?
a serious allergic reaction that is rapid in onset and may cause death
(T/F) Anaphylaxis is a type 1 hypersensitivity reaction.
T
What are the causes/triggers of anaphylaxis and anaphylactoid reactions?
food, drugs, stings, allergens, exercise, idiopathic
What is the most common trigger of anaphylaxis?
food
What is the most common manifestation of drug allergy?
urticaria
What are the main mechanisms by which stimuli cause anaphylactoid reactions?
direct mast cell activation, disturbances in arachidonic acid metabolism
What is the difference between true anaphylaxis and anaphylactoid reactions?
True anaphylaxis involves IgE antibodies binding to mast cells. Anaphylactoid reactions can be caused by alternative methods of getting mast cells to degranulate. The two are practically identical when observed clinically.
What are the patient-related factors which may contribute to anaphylaxis?
age, asthma and other respiratory diseases, concomitant diseases, atopy, previous history of anaphylaxis, concurrent medications, exercise, infections, stress
What are the two kinds of allergen?
complete protein, low molecular weight substances
(T/F) Complete proteins are capable of eliciting a complete antibody response by themselves.
T
What is the appropriate Th1 response to an allergen?
release of cytokines resulting in tolerance
What type of cell encounters and identifies allergens?
antigen presenting cells (APCs) e.g. macrophages
(T/F) Absence of cutaneous Ssx rules out anaphylaxis.
F
What is the most common Ssx observed in anaphylaxis?
urticaria and angioedema
How do you differentiate anaphylaxis from a vasovagal response based on observation of the CVS?
vasovagal response: BP and heart rate decrease
anaphylaxis: BP decreases, heart rate increases
How is the vomit of an anaphylaxis patient described?
stringy
What is the first-line treatment for anaphylaxis?
epinephrine
(T/F) Steroids are an effective substitute for epinephrine in anaphylaxis.
F
Which lab test would be most helpful to confirm the diagnosis of anaphylaxis? A. serum specific IgE levels B. skin testing C. serum tryptase level D. plasma histamine level
B.
