Allergic contact dermatitis Flashcards Preview

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Flashcards in Allergic contact dermatitis Deck (34):
1

allergy

exaggerated rxn of immune system following contact w/ foreign substance

2

allergen

substance that causes or elicits allergic rxn

3

eczema

red, itchy, weepy patches of skin

4

allergic contact dermatitis risks

anyone; atopy (predisposition for allergies)

5

allergic contact dermatitis happens how?

1) sensitiization or induction (first contact); 2) elicitation (develop rash after re-exposure)

6

How does sensitization to an allergy occur?

contact or open skin allows the loss of barrier fxn leading to first contact of allergy

7

Step 2 of allergic contact dermatitis occurs how?

2nd contact w/ allergen leads to memory T cells leading to elicitation of the rash

8

What are the Sx of acute allergic contact dermatitis?

itchy, red, crusting, blisters

9

What are the Sx of chronic allergic contact dermatitis?

itch (+/-); less red; hyperpigmentation; thickened skin; few blisters

10

Where does allergic contact dermatitis typically affect?

at site of contact to allergen

11

Describe the allergic contact dermatitis as a type IV HSR

Sx 24-48hrs later with faster rxns with more exposure leading to rash of 7-14 days with no hives or wheezing

12

What are distinguishable characteristics of rash from poison ivy?

linear pattern with Sx of mild itch to severe itch with blisters

13

T/F poison ivy can be spread in blister fluid

false

14

How can a person get poison ivy without direct contact?

urushiol is present in vines leading to spread by contact or in burning it in the air

15

What are some common allergic contact dermatitis allergens?

CHEMICALS => nickel; fragrances; preservatives; rubber products; topical antibiotics; plants

16

When should you be careful for nickel allergies?

piercing associated with jewelry, metal objects, clothing; medical devices

17

Other than nickel in outside objects, where else is it something to be wary of?

dietary nickel

18

What are the recommendations for nickel allergies?

avoid exposure to nickel compounds; low nickel diet

19

T/F Allergies to fragrances is 2nd most common allergy

true => many different components cause (natural and synthetic)

20

Where can fragrances be found?

most personal care products (even those that say unscented)

21

Where do fragrance allergies typically present?

face, neck, skin around eyes

22

How is testing for fragrance allergy done?

testing through "mixes" that contain many compounds

23

What is widely used in cosmetic, pharmaceuticals, and industrial application to prevent bacterial and fungal overgrowth?

preservatives (formaldehyde, parabens)

24

Where are reactions to preservative allergies typically found?

site of contact or relatively diffuse with testing needed to detect/confirm allergy

25

What are the types of rxns associated with rubber?

1) immediate type rxns to latex proteins (hives, itching, wheezing, anaphylaxis);
2) delayed type rxns to chem additives in rubber products (eczematous rxns)

26

A physician notices an immediate rxn when he got ready to do his procedure. What type of rxn does he probably have? How does it cause it?

latex allergy leading to immediate type HSR that can be found in latex glove powder

27

What can lead to bleached rubber syndrome?

use of chlorine bleach makes carbamates in elastic more allergenic

28

Topical antibiotics may lead to allergic rxns. What increases the likelihood of this happening?

topical antibiotics on open skin (dermatitis) may increase chance of developing allergy;
2 drugs cross reacting;
Rxns confused for infection

29

What is the gold standard for allergic contact dermatitis?

patch testing due to dermatologists being able to predict relevant allergens only 50% of time

30

What does prick testing test for?

immediate type hypersensitivity rxns (detects allergies in foods, trees, grasses, molds, pets)

31

What does patch testing test for?

delayed type HSR from chemicals, metals, preservatives, fragrances

32

How do you treat allergic contact dermatitis?

symptomatic relief with cool compresses, oatmeal bathes, calamine lotion; topical corticosteroids

33

What should you avoid in Tx of allergic contact dermatitis?

caladryl or product with topical benadryl which is potent sensitizer

34

What is an effective means to avoid delayed typic HSR for allergic contact dermatitis?

avoid the causative agent but NO ALLERGY SHOTS