Dermatitis and Eczema Flashcards
WHat are the three types of dermatitis we talked about?
atopic dermatitic (eczema)
contact dermatitis
seborrheic dermatitis
What happens in atopic dermatitis? Who get is?
It’s Eczema - usually childhood onset and 50% resolve by adolescence
it’s a chronic, pruritic condition of the skin of unknown etiology -
there seems to be a genetic suscptibility, immune dysfunction and epidermal barrier dysfunction leading to increased histamine and leukotriene production
What conditions are often found in people who have atopic dermatitis (eczema)?
asthma and allergies
Which antibody is elevated in atopic dermatitis (eczema)?
IgE
Even though eczema usually resolves, what are some poor prognostic features found in people with eczema in adulthood?
fam history
early disseminated in infancy
female
coexisting allergic rhinitis and asthma
What is the pathophysiology of dermatitis?
- epidermal edema (spongiosis)
- Pale epidermis
- swelling of keratinocytes
- leaky cells with fluid pockets
- clinically = weeping vesicles
What is the clinical hallmark of eczema?
“the itch that rashes”
VERY itchy
Where do kids usually get eczema on their bodies?
adults?
kids get it on their cheeks, chin, and extensor surfaces
adults with flexor surfaces, buttocks, neck, face, upper chest/ adults get lichenification
WHat percentage of children have eczema in the US?
What percentage of those affecetd also have a respiraotry allergy?
10%
80%
While there is definitely a genetic component to eczema, what are some environmental factors that could be involved?
pollutatns
indoor allergens
decline in breast feeding
What is the relation between allergenc and eczema?
the allergens don’t cause it, but they aggregate it and exacerbate the rash
What is the treatment of atopic dermatitis?
cutaneous hydration is huge (avoid soaps)
topical glucocorticoid Rx an option
newer prescriptions include protopic (an immunomodulator that inhibits T-ceel activation) and elidel (a calcineurin inhibitor)
What are two ways you can treat the pruritis of the eczema (the itchiness)?
antihistamines at bedtime
tar preparations
basically just moisturize
What are some additional optoins for refractory atopic dermatitis?
wet cressings
systemic glucocorticoids
phototherapy (PUVA)
Leukotriene inhibitors
Immunosuppressants
What are the main complications asociated with atopic dermatitis?
eyelid dermatitis can lead to corneal scarring, vernal conjunctivitis (inflammation of upper eyelid), keratoconus (conical deformity of the corna from chronic rubbing), cataracts
secondary infections (most common is HSV, but also fungal, staph aureus, HPV, molluscum)
Hand dermatitis
Exfoliative dermatitis
What are the two secondary infections that cause issues in atopic dermatitis?
bacterial impetigization from staph aureus
secondary herpetic infection causing eczema herpeticum
What is contact dermatitis?
An inflammatory reaction of the skin precipitated by an exogenous chemical
what are the two types of contact dermatitis?
irritant - direct toxic effect on the skin
allergic - immunologic reaction that causes tissue inflammation - occurs 24-48 hours after exposure (type 4 hypersensitivity)
What are 5 big examples of sensitizers for contact dermatitis?
poison ivy
paraphenylendiamine (in hair dyes)
nickel
rubber compounds
ethylenediamine (preservative in mycolog cream)
What will contact dermatitis from poison ivy look like?
erythematous vesicular rash in a linear pattern (usually)
it does NOT have to be only on the area of the skin that came in contact with the plant
WHat are some common locations on the body for contact dermatitis?
it depends on the trigger….
head and neck for cosmetics
scalp for hair dyes or shampoo
eyelids for cosmetics and nail polish
dorsum of hand for industrial chemicals
dorsum of feet for rubber and leather from shoes
Which types of contact dermatitis can be tested for and which can’t?
the allergic dermatitis can be tested for using the patch test
there it no testing for irritant contact dermatitis
What is the treatment for contact dermatitis?
prevent exposure to the allergen!
SYmptomatic therapy - drying agents for the vesicular weeping, oral anithistamines and glucocorticoids. Predisone is often necessary because the type 3 hypersensitivity reaction is internal.
wear barriers like gloves
tolerance induction to the known allergen
What is seborrheic dermatitis? What is the clinical hallmark?
It’s a chornic superficial inflammatory process affecting the hairy regions of hte body especially the scalp, eyebrows, ears, and face
It’s scaly!!!
People with what disease will almost always have seborrheic dermatitis?
HIV
People with diseases in what body system also have a tendency towards seborrheic dermatitis?
oddly enough, nervous system disorders like parkinson’s disease, dranial nerve palsis, and paralysis - maybe increased pooling of sebum from immobility…
When are the two age peaks in incidence of seborrheic dermatitis?
infancy int he first 3 months (cradle cap)
adults 40-70 yrs
How can you distinguish seborrheic dermatitis from atopic dermatitis in infants?
it’s hard, but it it’s affectig the diaper area and the axilla, it’s usually seborrheic dermatitis because atopic dermatitis tends to spare the diaper area
WHat are some drugs that can cause a seborrheic dermatitis-like rash?
arsenic
gold
methyldopa
cimetidine
neuroleptics (haldol, thorazine)
WHat time of year is seborrheic dermatitis most common?
late fall and winter
DOes PUVA help for seborrheic dermatitis?
no - it actually makes it worse
What are the treatment goals of seborrheic dermatitis?
loosening and removal of scales/crusts
inhibition of yeast colonization
control of secondary infection
reduction of erythema and itching
CONTROL, NOT CURE
What is the treatment for infants with cradlecap?
remove the drusts with salicylic acid in olive oil
can also use low potency glucocorticoids and mild baby shampoos
Is the use of soaps good for seborrheic dermatitis?
actually, yes - it removes oils form affected areas and improved the seborrhea
What is the treatment for seborrheic dermatitis in adults?
anti-inflammatories
anti-fungals
kerolytics like salicylic acid or coal tar preparations to remove the dense scale before topical steroids may be applied
Use daily champoo containing selenium sulfide, antifungals, zinc, benzoyl peroxide, salicylic acid, coal or juniper tar
WHat is photodermatitis?
An immune-based dermatitis in which UV light alters the antigen to make is an effective immunogen resulting in a type 4 cell-mediated reaction
commonly seen with thiazide diuretics and tetracyclines
STOP the med and use sunscreen
