pathogenic mechanism of skin disease Flashcards
stratum lucidum is seen in
feet/hands
Pemphigoid
Pemphigus
Dermatitis Herpetiformis
Autoimmune disorders resulting in bulla/blister formation
targets older patients (60-80yo)
Intensely pruritic red plaques and tense bullae
Histology shows a subepidermal blister on H&E
Direct immunofluorescence exhibits linear IgG and complement along the basement membrane
Autoantibodies targeting BP230 and BP180 antigens-components of hemidesmosomes.
Bullous pemphigoid
treatment of Bullous pemphigoid
calm down the inflammation by topical steroids
hemosdomes attacking process
Pemphigoid
split within the epidermis- katynocytes break apart process and has mucosal involvement
pemphigus
Flaccid bullae formed by intraepidermal acantholysis.
Pts typically age 40-60.
Lesions are painful rather than pruritic.
50-70% start with mucous membrane symptoms, but nearly all eventually have mucosal involvement.
Disease can be progressive without treatment.
Antibody mediated autoimmune disease targeting dsg3 primarily, as well as dsg1-both components of desmosomes.
Pemphigus vulgaris
treatment of pemphigus
need systemic treatment, tropical treatments are not enough
IgG process against the desmosomes
pemphigus
Associated with various systemic processes including lymphoma, adenocarcinoma, castleman’s, thymoma, and others.
paraneoplastic pemphigus
Intensely pruritic immunobullous disorder affecting extensor surfaces and lower back.
Rarely see blisters on exam-usually excoriated.
Often associated with a gluten enteropathy.
Autoantibody (IgA) to epidermal transglutaminase 3.
Neutrophil dominant disorder-IgA attracts neuts, as opposed to the IgG mediated BP and PV which attract eosinophils.
dermatitis herpetiforms
extensor skin involvement
dermatitis herpetiformis
IgA mediated process in the epidermal junction and associated with gluten
dermatitis herpetiformis
treatment of dermatitis herpetiforms
dapsone (also is used as a diagnostic tool) and diet-modification
Neural crest derived cells
5-10% of cells in the basal layer
Produce melanin that is then transported into neighboring keratinocytes
Role is protection from UV radiation
melanocytes
melanin is produced by _______ and transferred to ______
produced by melanocytes and transferred to kerationocytes
Absorbs most UV (~99%) radiation
Derived from tyrosine
Most humans express eumelanin
Redheads express pheomelanin-not as effective
melanin
oculocutaneous albinims is due to a defect in
tyrosine metabolism
normal melanocyte number but no melanin
albinism
Well demarcated patches of depigmentation
Complete loss of melanocytes
Pathogenesis unclear-autoimmune, cytotoxicity, genetics, etc.
vitiligo
melasma
increased activity of melanin due to increased hormones such as progesterone or estrogen maybe from OCP
-Patchy Hyperpigmentation commonly found in women
-Often involves the cheeks, forehead and upper lip
-More common in skin of color but may develop in anyone
-Often triggered by hormonal change
Oral Contraceptives
Pregnancy
melasma
