4. Acute Inflammatory and eczematous dermatoses Flashcards
Urticaria is commonly known as what?
hives
What is hives associated with?
mast cell degranulation
dermal microvascular hyperpermeability
What is acute hives
<6 weeks and associated with food and other allergens
What is chronic hives
> 6 weeks and associated with autoimmune disorders, thyroid dysfunctions, etc.
What are the causes of the increased vascular permeability associated with hives?
(5)
Contraction of endothelial cells
Retraction of endothelial cells
Direct injury of endothelial cells
Endothelial injury mediated by leukocytes
normal endothelial cell-to-cell binding
Transcytosis or vesiculovacuolar pathway
How long does it take hives to resolve?
1-4 days
What type of sensitivity is associated with erythema multiform and Steven Johnson Syndrome/Toxic Epidermal Necrosis?
Type IV
How can erythema multiforme be classified?
major and minor
What is erythema multiforme major?
Typical targets or raised, edematous papules distributed acrally with involvement of one or more mucous membranes; epidermal detachment involves less than 10% of total body surface area (TBSA)
What is erythema multiforme minor?
Typical targets or raised, edematous papules distributed acrally
SJS/TEN presents with
erythematous macules and mucous membrane erosion
What are the levels of epidermal detachment?
Steven-Johnson syndrome: < 10% Epidermal detachment
Toxic epidermal necrolysis: > 30% Epidermal detachment
Overlapping SJS/TEN: 10-30% epidermal detachment
Erythema multiforme can be classified by what characteristic compared to SJS/TEN?
infectious
SJS/TEN can be classified by what characteristic compared to Erythema multiforme?
drug induced
What cells release cytokines in the epidermis to mediate epithelial apoptosis and inflammatory reaction?
CD8+ T Cells
What cells release cytokines in the dermis to mediate epithelial apoptosis and inflammatory reaction?
CD4+ T Cells
What type of cytokine response is seen in the pathophysiology of erythema multiforme?
Transient TH1
What is the oral involvement of erythema multiforme?
shallow ulcerations localized to the inferior tongue and bilateral posterior mucosa
What type of hypersensitivity is associated to endogenous or exogenous stimuli in acute eczematous dermatitis?
Type IV
What is spongiosis?
widened intracellular spaces
What is allergic contact stomatitis?
dermatitis that occurs at the site of contact and includes itching and burning
what type of hypersensitivity is allergic contact dermatitis?
type IV hypersensitivity
what are the clinical features of allergic contact dermatitis?
Pruritic papules and vesicles on an erythematous base
what are the pathological features of allergic contact dermatitis?
extensive spongiosis
May have intraepidermal vesicles, perivascular lymphocytic infiltrates in the upper dermis, also numerous eosinophils
what is the pathogenesis of atopic dermatitis?
skin barrier defects: (FLG) Filaggrin and SPINK5 mutation
Atopic dermatitis in adults can be clinical seen as what?
brown macular ring around the neck
Pathological features of atopic dermatitis includes
acute to chronic spongiosis dermatitis
What may be used to rule out other conditions from atopic dermatitis
biopsy and lab test to see IgE levels
