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Flashcards in Hypersensitivity and the Skin Deck (14)
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1

Allergic contact dermatitis is associated with which type of hypersensitivity?

IV

2

Type 1 allergy has which steps in its pathophysiology?

Antigen exposure

Dendritic cells present antigen to specific T cells

TH2 cells are activated and release IL4, 5 and 13 

B cells are activated and begin IgE production

IgE induces mast cell degranulation

3

What is urticaria?

Red itchy skin rash associated with a type 1 hypersensitivity

4

What is the time frame for a type 1 hypersensitivity reaction?

Seconds to 2 hours

5

Which investigations can be used for type 1 hypersensitivity?

Skin prick

Challenge test (rarely recommended)

Serum mast cell tryptase levels

Specific IgE

 

6

Which type of investigation is associated with type IV hypersensitivity?

Patch testing

7

Which type of hypersensitivity is IgG mediated?

Type II

8

What is the gold standard for testing allergic contact dermatitis?

Patch testing

(allergic contact dermatitis is type IV hypersensitivity)

9

How is patch testing performed?

Allergens are attached to a patients back in separate chambers

Readings are taken to gaugue the respons eat 48 and 96 hours

10

What is the dosage for an adrenaline auto-injector in

a) Adults

b) Children

a) 300mcg

b) 150mcg

11

How quickly will and urticarial rash normally appear in type I hypersensitivity?

Within 1 hour

(usually last between 2 and 6 hours)

12

Why would an antihistamine be taken before an oral corticosteroid in the instance of food allergy?

Anti-histamines work quickly

(corticosteroids are more effective)

13

How is type IV hypersensitivity mediated?

T cells

14

For which reason is Coeliac disease not classed as an allergic condition?

It is not mediated by IgE