Allergy/Immunology Flashcards
Best way to exclude antibody deficiency
check for specific antibodies to haemophilus, pneumococci and tetanus
Note: Immunoglobulins and subclasses can be normal in the setting of specific
Henoch-Schonlein Purpura is an immune complex type 2 hypersensitivity reaction T/F
False - type 3; not 2
What are some features of non IgE mediated food allergy?
Eczema
FFT
Irritability
Reflux
What lab is abnormal in hereditary angio edema C3 or C4?
C4 will be low
C3 is always normal
Post strep glomerulonephritis is what type of hypersensitivity?
Type III - immune complex deposition
Other Type III: SLE, serum sickness, reactive arthritis
Immune complex deposition
Example of a type I hypersensitivity reaction?
Anaphylaxis
Mediated by mast cells
Type II hypersensitivity reaction examples?
Autoimmune haemolytic anaemia
Rheumatic heart disease
What are type IV hypersensitivity reactions mediated by?
T cell
Examples: contact dermatitis, Mantoux test , GVHD, rheumatoid arthritis
Different reasons for patch vs skin prick testing?
Patch is for late phase reactions - contact dermatitis to latex for example , drug allergies
Skin prick is for IgE mediated immediate reactions
DiGeorge syndrome is assoc with what immuno abnormality?
Absent T cells
Note: may have normal serum immunoglobulins but low antibody responses.
Bruton’s disease is assoc with what immuno abnormality?
Absent mature B cells
Cow’s milk protein intolerance can manifest as anaphylaxis and shock T/F
T
Can also have other features of allergy without anyphylaxis
Rheumatoid arthritis is what type of hypersensitivity reaction?
Type IV
Note: as are contact dermatitis, Mantoux test , GVHD
Involves T cell antigens, delayed
What leukotrienes are involved in anaphlyaxis?
B4, C4, D4 and E4
NOT A4
In anaphylaxis what % of patients will have a repeat episode within 8 hours?
More than 20%
What is the prevalence of food allergies in westernised countries?
About 5%
What pneumococcal vaccine protects against more serotypes the conjugated or unconjugated?
Unconjugated (30-40 serotypes)
Note: conjugated is only 13 serotypes
What system is most commonly affected by IgE mediated cows’ milk protein allergy?
Skin
What system is most commonly affected by non IgE mediated cows’ milk protein allergy?
GI
Note: non IgE is delayed hypersensitivity
How is scombroid fish allergy mediated?
It is a histamine overdose - it occurs as a result of bacterial overgrowth producing the scombroid toxin.
Note: it is not IgE mediated and not a true allergy but an overdose as stated above