Pathology - derm Flashcards
Layers of the epidermis
Corneum Lucidum Granulosum Spinosum Basale
Claudins and occludins
Tight junctions
Cadherins and action cytoskeleton
Adherens junction
Keratin and desmoplakin
Desmosome
Connexons
Gap junction
Keratin and basement membrane
Hemidesmosome
Integrins
Membrane proteins that attach to basement membrane
Hyperkeratosis
incr. thickness of stratum corneum
Acanthosis
Epidermal hyperplasia (incr. spinosum)
Normal melanocyte number with decr. melanin production
Albinism
Decreased tyrosinase activity, or defective tyrosine transport
Also caused by failure of neural crest migration during development
Autoimmune destruction of melanocytes
Vitiligo
Irregular areas of complete depigmentation
Inflammation of pilsebaceous unit
Acne
Pruritic eruption on flexor areas
Atopic dermatitis (eczema)
Face in infancy, then elbow fossa
Acanthosis with hyperkeratosis
Psoriasis
incr. spinosum, decr. granulosum (SSSS: soriasis, spinosum)
Pinpoint bleeding when scales are scraped off - Auspitz sign
Squamous epithelial proliferation with keratin-filled cysts
Seborrheic keratosis
If sudden appearance of multiple, then indication of underlying GI/lymphoid cancer
Location of edema in urticaria
Dermis
look for lymphatic dilation as well. Mediated by mast cell degranulation
Staph scalded skin syndrome
Exotoxin destroys keratinocyte attachments in granulosum only
heals completely
Toxis epidermal necrolysis
Destruction of epidermal-dermal junction
IgG antibody against desmoglein (desmosome component)
Pemphigus vulgaris
Acantholysis, flaccid intraepidermal bullae
IgG antibody against hemidesmosome
Bullous pemphigoid
linear immunofluorescence at epidermal-dermal junction (Abs are “bullow” the epidermis)
IgA at tips of dermal papillae
Dermatitis herpetiformis
Assoc. with celiac disease
Associations with acanthosis nigricans
hyperinsulinism
gastric adenocarcinoma
Sawtooth infiltrate of lymphocytes at dermal-epidermal junction
Lichen planus
assoc. with hep C
pruritic, purple, polygonal planar papules and plaques
UVA vs. UVB rays
UVA - tanning, photoaging
UVB - sunburn
Pink pearly nodules with telangiectasias, rolled borders, central crusting
Basal cell carcinoma
Palisading nuclei
Ulcerative red lesions with frequent scale, may spread to lymph nodes
Squamous cell carcinoma
Keratin pearls
Activating mutation in BRAF kinase, V600E
Melanoma
Tx: vemurafenib
