Derm Flashcards
Junctional nevi
FLAT
black to brown pigemented macules
Compound Nevus
Aggregates of nevus extend into dermis
RAISED PAPULES, with uniform brown to tan pigmentation
*has both dermal and epidermal involvemnt
Older lesion in which epidermal nests of nevous cells have been lost
Intrademeral Nevus
Remaining dermal nevus lose tryosinase activaty and produce little ot no pigement
Skin to tan colored, dome shaped, sometimes peducualted
Hyperkeratosis
Parakeratosis
Psoriasis
hyperkeratosis = increased thickness of stratus corneum
Parakeratosis - hyperkeratosis with retention of nuclei in stratum corneum
Normal melanocyte number with decreased melanin production
Decreased tyrosinase activity or defective tyrosinase tranpsort
**can also be caused by failure of neural crest cell migration during development
Albinism
Autoimmune destruction of melanocytes
Vitiligo
Acantholysis
Separation of epidermal cells = Pemphigus Vulgaris
Subepidermal nonacantholytic blisters
Bullos Phemphigoid
Epidermis separates from the dermis
Abs to hemidesmosomes
Role of metalloproteases
Degradation of collagen and other proteins in the extracellular matric
Important in wound healing
Encourages myofibroblasts accumulation at wound edges and scar tissue remodeling
Role of myofibrobalsts in wound healing
Initiate wound contraction during healing by second intention
High metalloprotease activity = high myofibroblasts = excessive wound contraction = contractures
Actinic keratoses may transform into what over several years?
Invasive squamous cell carcinoma
Auspitz sign
Psoriasis
Pinpoint bleeding spots from exposure of dermal papillae when scales are scraped off
+ Nikolsky sign
Pemphigus Vulgaris
- Separation of epidermis upon manual stroking of skin
- can also involve oral mucosa
Sudden appearance of multiple seborrheic keratoses
Leser-Trelat sign
Indicates an underlying malignancy, usually GI
Why is a freckle dark?
Increased numbers of melanosomes
NO INCREASED MELANOCYTES
