week 3 lec 1 Flashcards
atopic dermatitis causes
familial transmitted skin disease
–> genetic, immune, environmental risk factors
when does atopic dermatitis usually begin
childhood
hallmark symptom of atopic dermatitis
itch (can effect sleep, cause excoriations and infections)
co-morbidities with atopic demaitits
allergic asthma and allergic rhinitis
major features of atopic dermatitis
chronic or chronically relapsing
- Pruritus
- Eczematous dermatitis (acute, subacute, or chronic) -
- Facial and extensor involvement in infancy
- Flexural eczema or lichenification in children and adults
atopic dermatitis is commonly associate qith
family history of atopy (allergic rhinitis, Asthma, AD)
xerosis or skin barrier dysfunction
IgE reactivity
pathogenesis of atopic dermatitis is driven by
skin barrier defect (FLG gene)
environment
altered immunologic responses in T cells, antigen processing, inflammatory cytokines, host defense proteins, allergen sensitivity, and infection.
types of atopic dermatitis
eczema
contact dermatitis
seborrheic dermatitis
atopic dermatitis etiology
3x prevalence since 1960s
more in industrialized countries 10-20%
more females
acute lesion characteristics in a topic dermatitis
erythematous papulovesciles (small red bumps or blisters)
surface changes; pinpoint crusting or weeping from exudation
sxz: prurits –> itchy
subacute or chronic lesions in atopic dermatitis
dry, scaly plaques
excoriation and lichenification
pruritis, less erythema than acute
atopic dermatitis lesions
can have acute and chronic lesions
multiple areas
indistinguishable clinically or historically from other eczematous conditions like allergic contact dermatitis and nummular dermatitis
patients with darker skin and atopic dermatitis
follicular accentuation
flat-topped papule in lichenified areas
hyperpigmentation
(rare) vitiligo like depigmentation
infancy - which area on body for atopic dermatitis
face, scalp, extensors
adolescent with atopic dermatitis is usually on which area
flexural folds
(lichenification and chronic)
adults primary location for atopic dermatitis
hand eczema
also more flexural and around neck
1/3 of patients with atopic dermatitis have features of _____ deficiency
filaggrin deficiency
–> ichthyosis vulgaris, keratosis pilaris, and hyperlinear palms.
other features in atopic dermatiits
allergic shiners below eyes
conjunctivitis
elevated IgE
facial pallor
etc
comorbidities of atopic dermatitis
Th2 immune activation
high IgE
eosinophilia
predisposed to other allergies
psychosocial (anxiety/depress)
complications of atopic dermatitis
Bacterial, Viral, Fungal infections
Ocular Issues (eyelid dermatitis, etc)
Hand dermatitis
Exfoliative dermatitis
what is exfoliative dermatitis (complication of AD)
generalized (90% of body) redness, scaling, weeping, crusting, systemic toxicity, lymphadenopathy, and fever. Although this complication is rare, it is potentially life threatening
skin barrier function decreased in atopic dermatitis
-downregulate cornified enveloped genes (keratin, filaggrin, loricrin)
-reduced ceramide levels
-increase endogenous proteolytic enzyme activity
-enhance trans-epidermal water loss
scratching and exogenous proteases (ie. dust mites and s. aureus) impact barrier too
increase allergen absorption
lack endogenous protease inhibitors
soap and detergents effect skin barrier in AD
raise pH, increase endogenous protease activity –> further breakdown of epidermal barrier function
genes in atopic dermatitis
loss of function in filaggrin (chromosome 1q21)
–> effect barrier function: increase trans-epidermal water load, increase allergen and chemical entry, inflammatory response