MTB Allergy and immunology Flashcards
List 3 examples of the contents of a mast cell granules
- leukotrienes
- histamine
- histamine
in anaphylaxis - IgE binds mast cells and causes degranulation of the mast cell. Contents of these granules are released leading to anaphylaxis.
How does an anaphylactoid rxn differ from anaphylaxis?
Anaphylactoid rxn does not require priming by prior exposure to the Ag and does not involve IgE, while anaphylaxis does require prior exposure and is IgE mediated.
They are clinically identical
What is the presentation of anaphylaxis?
- Hypotension, tachycardia
- Respiratory: SOB; wheezing; swelling of lips, tongue, or face; stridor
- Rash (as with any allergic rxn)
What is the tx for anaphylaxis?
- epinephrine
- Antihistamines - diphenhydramine (H1 blocker) and ranitidine (H2 blocker)
- Glucocoritcoids - methylprednisone or hydrocortisone
- if needed - airway protection - intubation or cricothyroidotomy
What is angioedema?
Sudden swelling of:
- face
- Tongue
- Eyes
- Airway
What is a possible cause of a propensity towards developing angioedema?
C1 esterase inhibitor deficiency
Define hereditary angioedema, does it respond to glucocorticoids?
sudden facial swelling and stridor with absence of pruritis and urticaria
Hereditary angioedema does NOT respond to glucocorticoids
How do you diagnose angioedema?
How do you treat it? - initial, acute, long term
Dx - check for decreased C2 and C4 levels and a deficiency of C1 esterase inhibitor
Tx:
-initial - secure airway
- acute: plasma and Ecallantide
- long term: Androgens - Danazole or Stanazole
What is a specific therapy for andioedema?
Ecallantide –> inhibits Kallikrein
List 3 causes other than medication and insects that can cause urticaria.
pressure, cold, vibration
How do you tx urticaria?
- antihistamines - hydroxyzine, diphenhydrapmine, fexofenadine, loratidine, cetirizine, ranitidine
- Leukotriene receptor antagonist: montelukast or zafirlukast
What are some common causes of allergic rhinitis?
seasonal allergies, hay fever
this is IgE triggered degranulation of mast cells
In someone with allergic rhinitis - what would you expect to see in a nasal smear?
large number of eosinophils
List 5 treatments for allergic rhinitis.
- prevention with avoidance of the precipitating allergen
- Intranasal corticosteroid sprays
- Antihistamines: loratadine, clemastine, fexofenadine, bropheniramine
- intranasal anticholinergic medications - ipratroprium
- desensitization to allergens that cannot be avoided
Describe common variable immunodeficiency, what Igs are decreased in this condition?
B cells are produced in normal amounts but they do not make effective amounts of immunoglobulins.
Decreased IgG, IgM, IgA
decreased response to antigen stimulation of B cells
decrease in the output of B lymphocytes with a normal number of B cells as well as normal amounts of lymphoid tissue - nodes, adenoids, tonsils
