Allergic contact dermatitis

Question 1

allergy

Answer 1

exaggerated rxn of immune system following contact w/ foreign substance

Question 2

allergen

Answer 2

substance that causes or elicits allergic rxn

Question 3

eczema

Answer 3

red, itchy, weepy patches of skin

Question 4

allergic contact dermatitis risks

Answer 4

anyone; atopy (predisposition for allergies)

Question 5

allergic contact dermatitis happens how?

Answer 5

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

Question 6

How does sensitization to an allergy occur?

Answer 6

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

Question 7

Step 2 of allergic contact dermatitis occurs how?

Answer 7

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

Question 8

What are the Sx of acute allergic contact dermatitis?

Answer 8

itchy, red, crusting, blisters

Question 9

What are the Sx of chronic allergic contact dermatitis?

Answer 9

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

Question 10

Where does allergic contact dermatitis typically affect?

Answer 10

at site of contact to allergen

Question 11

Describe the allergic contact dermatitis as a type IV HSR

Answer 11

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

Question 12

What are distinguishable characteristics of rash from poison ivy?

Answer 12

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

Question 13

T/F poison ivy can be spread in blister fluid

Answer 13

false

Question 14

How can a person get poison ivy without direct contact?

Answer 14

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

Question 15

What are some common allergic contact dermatitis allergens?

Answer 15

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

Question 16

When should you be careful for nickel allergies?

Answer 16

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

Question 17

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

Answer 17

dietary nickel

Question 18

What are the recommendations for nickel allergies?

Answer 18

avoid exposure to nickel compounds; low nickel diet

Question 19

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

Answer 19

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

Question 20

Where can fragrances be found?

Answer 20

most personal care products (even those that say unscented)

Question 21

Where do fragrance allergies typically present?

Answer 21

face, neck, skin around eyes

Question 22

How is testing for fragrance allergy done?

Answer 22

testing through “mixes” that contain many compounds

Question 23

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

Answer 23

preservatives (formaldehyde, parabens)

Question 24

Where are reactions to preservative allergies typically found?

Answer 24

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

Question 25

What are the types of rxns associated with rubber?

Answer 25

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

Question 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?

Answer 26

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

Question 27

What can lead to bleached rubber syndrome?

Answer 27

use of chlorine bleach makes carbamates in elastic more allergenic

Question 28

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

Answer 28

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

Question 29

What is the gold standard for allergic contact dermatitis?

Answer 29

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

Question 30

What does prick testing test for?

Answer 30

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

Question 31

What does patch testing test for?

Answer 31

delayed type HSR from chemicals, metals, preservatives, fragrances

Question 32

How do you treat allergic contact dermatitis?

Answer 32

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

Question 33

What should you avoid in Tx of allergic contact dermatitis?

Answer 33

caladryl or product with topical benadryl which is potent sensitizer

Question 34

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

Answer 34

avoid the causative agent but NO ALLERGY SHOTS