Eczema and Itchy Skin Flashcards
What is the definition of eczema?
basically synonymous with “Atopic Dermatitis”
a red, itchy, scaly/flaky, sometimes oozing rash that can affect kids and adults
usually chronic, but frequently kids grow out of it
What are the histologic findings of eczema?
inflammatory dermis - lymphocytic perivascular infiltrates
abnormal maturation
acanthotic epidermis
What is the distribution of eczema at various ages?
baby - cheeks, trunks, extremities (extensors)
child - antecubital and popliteal fossae (flexors)
teen/adult - neck, flexors, hands and feet
What are some theories for the cause of eczema?
genetics
pollution
hygiene hypothesis - our society is not too clean, overreaction of immune system
What are some possible causes of eczema?
xerosis
internal or metabolic problems
acute virus infection
contactants
antigen - antibody reaction
acute bacterial infection
sweat retention and scratching
itchy skin
psyche
ichthyosis vulgaris
hyperlinear palms, dry pretibial palms
form of very dry skin, can predispose people to eczema
What is the role of filaggrin?
filament-aggregating protein
binds to keratin fibers and helps hold cells together and prevents water loss
provides mechanical strength and plays a role in calcium management
degrades to Natural Moisturizing Factor (NMF)
breaks down into organic acids for pH (acid mantle)
What happens when filaggrin is mutated?
ichthyosis vulgaris (IV)
8% of eczema patients have features of IV
between 15-56% of eczema patients carry one or more filaggrin null mutations
about 13% of eczema may be due to filaggrin mutations on a population scale
What are the areas that should be treated for an eczema patient?
anti-inflammatory
anti-pruritic (itching)
antibiotics
moisturization
What are the anti-inflammtory treatments for eczema?
topical steroids are the mainstay of treatment
ointments are generally preferred
Stoughton Scale
vascoconstrivtor assay, ranks potency from 1-5
correlates well with clinical effectiveness
What are the risks of topical steroids?
atrophy, striae, dyspigmentation, hypertrichosis
hard to damage in < 2 weeks
the risks must be weighted against the benefits
What is the maintenance therapy of eczema?
maintenance tacrolimus twice weekly when eczema clears
effective in reducing the number and frequency of disease exacerbations and improving health-related QoL
What happens when kartinocytes differeniate in the presence of IL-4 and IL-13?
significantly reduced filaggrin gene expression
What is the role of moisturizer in eczema treatment?
correlates with decreased eczema
may be able to preventeczema
What are the common antibiotics used to treat eczema?
oral - cephalexin and diclox
muciprocin
bleach
What is the role of dilute bleach baths in the treatment of eczema?
study shows that it decreased the clinical severity of eczema significantly at 1 and 3 month visits
may play a role in suppressing bacterial infections
What are commonly used antipruritics?
sarna sensitive (1% Pramoxine)
aveeno anti-itch (3% Calamine, 1% Pramoxine HCl, 0.47% Camphor)
hydroxyne or cetirizine
doxepin (TCA)
What is allerci contact dermatitis?
type IV (delayed type) T-cell-mediated inflammatory reaction characterized by erythema, scaling, xerosis, and vesiculation, occurring at the site of challenge with a contact allergen in sensitized individuals
takes hours to days to appear and lasts for days to weeks (unlike type I hypersensitivity)
What is the treatment for contact dermatitis?
avoiding allergen is key, but first must find it first
can otherwise be treated just like eczema
patch testing - take a tiny bit of chemicals, in a few days take the chamber off
What is urticaria?
appears shortly after exposure to offending agent and resolves rapidly after cessation - evanescent!
hallmark - changing within 24 hours, dermatographism
may have cyclical, annular gyrate forms
What is the treatment for urticaria?
stop offending agent
monitor for signs of anaphylaxis
epinephrine if indicated
antihistamines
systemic corticosteroids if severe
