Allergic Rhinitis Flashcards
Allergic rhinitis has a strong genetic predisposition.
Okay
How does (Dr. Phillips say that) global warming may be increasing allergies?
Increased pollen.
More allergenic plants…
What’s the Th1/Th2 paradigm?
Th1 and Th2 responses suppress each other.
If you don’t have enough Th1, you’re going to get more Th2 -> IgE -> atopic diseases.
(this very oversimplified, though.)
What’s the receptor for IgE for mast cells, etc?
Fc epsilon RI
Do mast cells die when they degranulate?
No - they regenerate after about 36 hours.
How can you ID eosinophils on EM?
G2 granules - football shape bisected by darker line.
Most important factor that mast cells release when IgE binds?
Histamine - it’s preformed.
When mast cells are activated, some inflammatory mediators are synthesized (i.e. not preformed). Examples of such molecules?
Derivatives of arachidonic acid: (Phospholipase A2 activity is stimulated..)
- Prostaglandins
- Thromboxanes.
- Leukotrienes.
3 cell types that release inflammatory mediators in response to IgE bindings?
Basophils
Mast cells
Eosinophils
4 aspects of diagnosis of allergic rhinits?
History.
Exam.
Allergy testing.
Therapeutic trial.
Why are people commonly allergic to dust mites?
Mite excrement has sulfonamide moeities in it…
You guys know about the symptoms of allergic rhinitis.
Yeah. Discharge is clear. Usually no fever or pain.
Physical findings of allergic rhinitis?
Heliotrope* mucosa. Boggy turbinates. Clear discharge. Conjuctivitis. Allergic "shiners" - dark, swelling around eyes. Nasal crease (from upward nose-wiping).
*Heliotrope = pinkish-purple (it’s a flower).
What do you see on nasal smear of allergic rhinitis?
Usually >25% of cells are eosinophils.
What’s RAST?
Testing for IgE against a particular Ag.
