Dermatology Flashcards
Atopic dermatitis
is what type of hypersensitivity rxn
and is associated with elevated serum____?
type 1 hypersensitiivity rxn
elevated eosinophils
which Cytokine induces pruritis?
IL-31
IgG antibodies against desmoglein of keratinocytes. what disease?
pemphigus Vulgaris
(NOT bullous pemphigoid which is IgG to hemidesmosomes)
intact superficial layers of epidermis become dislodged with lateral pressure/shear forces
what is the sign called?
Nikolsky sign.
positive in pemphigus
Psoriasis is what type of hypersensitivity?
type IVa
or T cell mediated disease
CD4 TH1 –> TNF, IFN gamma
Auspitz’s sign is seen in?
psoriasis
bleeding points develop when the sclae is removed.
PSORIASIS
dianosis is clincal. however you will see what on histo?
loss of stratum granulosum
Acanthosis with PARAKERATOTIC (the keratinocytes of the stratum corneum are retaining the nuclei) SCALING
Allergic contact dermatitis
is what type of HSR
delayed, cell-mediated Type IV hypersensitivity reaction.
what is the mechanism of albinism?
normal melanocyte number with dec melanin production. due to decrease ****TYROSINASE enzyme activity or defective tyrosine transport
what is Vitiligo ( hands turning white aka depigmentation) cause?
caused by autoimmune destructin of melanocytes. (dec number of melanocytes)
antibodies to tyrosinase.
melanocyte embryologic origin?
neural crest
this skin disorder is mc associated with (HSV, Mycoplasma pneumoniea) infections, Drugs (sulf, B-lactams, phenytoin,.
presents with multiple types of lesions (macules, papules, vesicles) ** target lesions (looks like targete w/ multiple rings, and dusky center (necrosis) showing epithelial distruption.
what is this disorder?
Erythema multiforme.
Psoriasis. is casued by excessive keratinocyte proiferation involving the PSORS1
what type of HSR is this
type IV HSR (Th1 cell mediated)
IFN-Gamma & IL-12 –> Th1 differentation –> macrophages and T-cell recruitment –>. cytokine cascade.
what type of hypersensitivity is pemphigus vulgaris?
type 2 HSR
on immunofluorescence of pemphigus vulgaris. you expect to see?
antibodies around epidermal cells in a reticular (net like) pattern.
tombstoning pattern ( still basal keratinocytes on basal membrane bc hemidesmosomes not targeted)
pt that is 20-30 yo complains of extreme itchy lesions (papules,vesicles, bullae) on elbows.
on direct immunoflurescence you see IgA deposition in dermal-epidermal junction and dermal papillae.
on microscopy you see subepidermal bulla (very neutrophilic)
how would you treat this?
pt has dermatitis herpetiformis. which is associated with celiac disease
tx dapsone, gluten free diet
type III HSR
note: neutrophil is IgA driven.
