19. Skin Pathoma Flashcards
What are the layers of the epidermis? from surface to deep. what are found in each
Stratum Corneum (keratin)
Lucidum
Granulosm
Spinosum (desmosomes)
Basale (stem cells)
Whats atopic dermatitis?
where does it usually appear?
what type of hypersensitivity?
aka Eczema
face and flexor surfaces
TYPE I
Contact Dermatitis
what type of hypersensitivity
tx?
Poison Ivy, Nickel, neomycine
Type IV (delayed)
-remove offending agent/topical steroids
Acne
whats it due to?
what type of infection
tx?
comedones (white heads and black heads), pustules (pimples)
Chronic inflammation of the hair follicles and sebacious glands
Proprionibacterium acnes (P. acnes)
-retinoids, benzoyl peroxide, antibiotics
Psoriasis
whats it look like/ where is it found
whats another clinical sign it can be found with?
whats Auspitz sign?
tx?
excessive keratin proliferation: Parakeratosis (nuclei still in Stratum Corneum)
well-circumscribed “salmon colored” plaques with silvery scales
- extensor surfaces and scalp
- nail pititng
Auspitz: pinpoint bleeding after removing a scale
-corticosteroids/
Lichen Planus
how does histo look?
which other infection is it associated with?
Pruritic, purple, polygonal planar papules and plaques
- Sawtooth infiltrates of Lymphocytes at dermal-epidermal junciton
- Hep C
Pemphis Vulgaris
whats histo like? what layer is messed up
whats the clinical sign/finding?
what does immunoflourescence look like?
which type of skin does it involve?
Autoimmune destruction of Desmosomes via IgG antibodies
-tombstone appearance since basment cells are intact while the Stratum Spinosum is fucked up
- Separation of epidermis upon touching the skin (wet blisters)
- Net-like
- skin and oral mucosa
Bullous Pemphigoid
what will immunoflourescene look like?
how do the blisters look?
Autoimmune Destruction of Hemidesmosomes via IgG antibodies
-Linear pattern
oral mucosa isnt affected
-Tense Blisters that dont rupture easily
Dermatitis Herpetiformis
what do the lesions look like?
what dz is associated?
how do you treat it?
Depositions of IgA at tips of dermal papillae.
- -*herpes; so tiny vesicles that are grouped together
- Celiac dz
-dapsone/gluten free diet
Erythema Multiforme
what kind of skin lesions?
what are some associations?
Hypersensitivity reaction w/ Target Lesions
-HSV, M. pnuemo, sulfa drugs
Steven Johnson Syndrome
whats TEN?
Erythema Multiforme w/ oral mucosa and Fever
-Toxic epidermal necrosis: Sloughing off of the skin
Sborrheic Keratosis
whats it called when you have a sudden appearance of these?
morgan freeman, looks stuck on
Leser-Trelat sign: sudden onset, usually a sign of malignancy (usually GI)
Acanthosis Nigricans
(thick epidermis) (dark)
what is it? where is it usually found?
what causes/associated with it?
Thickening of the skin
usually on the groin or axilla
-diabetes, obesity, cushings, malignancy
Basal cell carcinoma of the skin
what are the risk factors?
whats it look like?
whats a key finding on histo?
tx
most common skin cancer
- exposure to UV sunlight
- raised lesion/central ulcer/dilated blood vessels (telangiectasias)
- palisading nuclei
- tx: excision
Squamous cell Carcinoma of the skin
what are some risk factors?
where is it usually found?
tx
whats usually its precursos
malignant proliferation of squamous cells
- sunlight, immunosupression, arsenic
- LOWER LIP
- excision
- Actinic keratosis
Actinic Keratosis
precursor to squamous cell
Keratoacanthoma
well differentiated SCC
volcanic lesion that forms quickly and resolves quickly as well
what level in the skin are mealoncytes found?
what embryo structure is it derived from?
where does it synthesize melain?
in the Basal cells
- neural crest
- synthesizes melanin in the melanosome
Vitiligo
Autoimmune destruction of the melanocytes
- localized loss of skin pigmentation
Albinism
whats the enzyme defect?
what are the 2 types?
what can it lead to?
Congenital lack of pigmentation
–defect in Tyrosine transport (impairs melanin production)
- eyes or eyes/skin
- increased risk of skin cancer
why are freckles present/darker than rest of skin?
they have increased number of melanosomes in their cells
whats Melasma?
hyperpigmentation of the cheeks associated with pregnancy or OCP use
Nevus (moles)
whats a junctional nevus?
Junctional: increased melanocytes at dermal-epidermal junction. these guys are Flat
Melanoma
subtypes: nodular/lentiginous/acral
Malignant neoplasm of melanocytes
most common cause of Death in skin cancer
nodular: bad prognosis, creates huge bump
lentignious: good prognosis (radial prolif along the dermal epidermal junction)
acral: on the hands and feet of dark skinned ppl
