Eczema Flashcards
1
Q
Contact dermatitis can be what two things?
A
- irritant (MC): acute or chronic inflammation of the dermis/epidermis as a result of direct irritation to the skin
- allergic: delayed type hypersensitivity rxn to contact allergen
2
Q
RFs to contact dermatitis
A
- frequent handwashing or water immersion
- atopic dermatitis (d/t barrier dysfunction)
- genetics
- environment
- increased exposure to allergens
3
Q
patho of irritant contact dermatitis
A
- no immune response
- can occur w/ first exposure
- disruption of epidermal barrier by chemicals or physical irritants –> damage to cell membrane –> cytotoxic effect on skin cells
4
Q
patho of allergic contact dermatitis
A
- requires an initial exposure and sensitiziation to allergen
- only occurs in susceptible individuals
- repeat exposure leads to type IV hypersensitivity rxn
5
Q
common causes of irritant contact dermatitis
A
- hand washing
- soaps
- saliva
- urine/feces
- high concentrations of most chemicals
6
Q
common causes of allergic contact dermatitis
A
- nickel and other metals
- hair products
- solvents (toluene)
- additives to meds and cosmetics
- rubber
- fragrances (balsam of Peru)
- clothing dyes
- formaldehydes
- topical abx
- plants
7
Q
what is a major topical antibiotic that causes allergic contact derm?
A
NEOMYCIN!
8
Q
timing of the development of both types of contact dermatitis
A
- irritant: immediately
- allergic: 48-72 hrs or longer after exposure
9
Q
hx in contact dermatitis
A
- when
- where
- shape
- size
- itchy or not
- burn or painful
- warmth
- used anything to tx
- better or worse
- child have it?
10
Q
PE in contact derm
A
- acute: mild skin dryness and erythema to eczematous papules and patches, edema, vesicles, and oozing
- chronic: lichenification, erythema, hyperkeratosis, cracking, scaling
11
Q
what test distinguishes irritant and allergic contact derm?
A
epicutaneous patch testing
12
Q
Ddx in contact dermatitis
A
- urticaria
- atopic dermatitis
- drug eruption
- nummular eczema
- bullous pemphigoid
- virus
13
Q
diaper dermatitis
A
- erythematous, scaly, eroded painful lesions w/ sparing of the creases***
- in candida dermatitis: bright BEEFY red in creases w/ satellite lesions
14
Q
atopic dermatitis
A
- chronic, relapsing pruritic eczematous condition affecting characteristic sites
- MC begins in infancy or early childhood
- usually fam hx of atopy (asthma, rhinitis)
15
Q
RFs for atopic dermatitis
A
- genetic predisoposition
- mutation in the filaggrin gene
- “itch-scratch cycle”
- associated w/ food sensitivities, hyper-IgE syndrome, IL-31 upregulation
