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Clinical Pathology > 10 Allergy > Flashcards

Flashcards in 10 Allergy Deck (17)
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1
Q

What is the body’s response to parasitic disease?

A

Increased IgE levels.
Tissue inflammation with eosinophils, basophils and mastocytosis.
Presence of CD4+ T cells secreting IL4, IL5, IL13.

2
Q

What is the hygiene hypothesis?

Proposed mechanism?

A

Stimulation by microbes is protective against autoimmunity.

Th1 Th2 deviation - if Th1 (infection) has nothing to work on Th2 increases.

3
Q

Which genes have influences on the ‘allergic’ immune response? (5).

A
Cytokine gene cluster IL3,5,9,13
IL12R, IL4R.
FcεRI.
IFNγ.
TNF.
4
Q

Beginning with a Th2 cell, how is mast cell degranulation achieved>

A

Th2 cell uses IL4 and IL13 to stimulate B cell into proliferating and producing IgE. IgE binds to sensitised mast cells which degranulate.

5
Q

Mast cells have initial and late phase responses, which chemicals characterise both?

A

Initial: histamine, proteases, chemotactic factors (ECF, NCF).
Late: Arachidonic acid derivatives - leukotrienes, prostaglandin.

6
Q

What is the atopic triad diseases?

A

Asthma, rhinitis, eczema.

7
Q

What is rhinitis? What are the common allergens?

A

Allergic response in upper respiratory tract and eyes.

Animal dander, pollen, house dust mite.

8
Q

Rx for rhinitis?

A

Antihistamines and nasal steroids.

9
Q

What is allergic asthma?

A

IgE mediated allergy. Late phase response causes away damage. Damaged tissue becomes hyper-reactive to other stimuli e.g. fumes.

10
Q

What is atopic dermatitis? Rx?

A

Allergy resulting in blistering, itching, cracking of skin. Major trigger is dust mite.
Rx: topical steroids and moisturisers.

11
Q

What is the trinity of interplaying factors in atopic dermatitis?

A

Barrier disruption.
Parities/itch.
Development of AD (Th2).

12
Q

Which tests are available to diagnose anaphylactic reactions? (6).

A
Specific IgE (>0.35KuA/L)
Skin prick test (>3mm wheal).
Intra-dermal test.
Oral challenge (gold standard).
Basophil activation test (research, not clinical).
Component resolved diagnostics.
13
Q

How is a skin prick test carried out?

Which drugs common affect this test?

A

-ve control (saline), +ve control (histamine), exposure.

Anti-histamines and tri-cyclic antidepressants.

14
Q

What are the symptomatic therapies for anaphylactic reactions? (3).

A

Anti-histamines.
Steroids.
Adrenaline.

15
Q

What are the indications for immunotherapy for anaphylactic allergies? (3).

A

Life-threatening reaction to wasp/bee sting.
Severe hay fever.
Animal dander allergy.

16
Q

What is the mechanism behind immunotherapy?

A

Purposeful exposure to allergen at increasing doses. Try to divert Th2 to Th1 response. Induce Treg cells and stimulate B cells to increased antibody competition.

17
Q

What are the clinical manifestations of a food allergy? (5).

A
D+V.
Bronchospasm.
Urticaria.
Angiodema.
Anaphylaxis.

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