Skin Pathology Flashcards
what cells make up the epidermis
keratinocytes and sq epi cells
what are the layers of the epidermis
corneum lucidum granulosum spinosum basale
what lies in the dermis
blood vessels, glands, follicles, nerves
changes in hyperkeratosis
inc s. corneum and inc keratin
parakeratosis
thickening of skin due to scratching
changes in acanthosis
inc s. spinosum
changes in acanthylosis
dec in adhesions between keratinocytes
what is spongiosis
intracellular oedema between keratinocytes
4 inflammatory patters
vesiculobullous - forms bulla
spongiotic - becomes oedematous
psoriaform - thickened
lichenoid - forms sheeny plaque
3 types of eczema/dermatitis
atopic
contact (TIV hypersensitivity)
suborrhoeic (inflam R to yeast)
acute changes in eczema/dermatitis
spongiosis, inflam infiltrate in dermis. dilated capi
chronic changes in eczema/dermatitis
acanthosis, crusting, scaling
presentation of psoriasis
well demarcated salmon-pink scaly plaques on knees, elbows and scalp
path of psoriasis
rapid turnover of keratinocytes -> thicker epidermis, S granulosum disappears
layer of parakeratosis on top
what are munro’s microabscesses
change seen in psoriasis
abscess (collection of neutrophils) in the s corneum due to the infiltration of neutrophils from papillary dermis
what nail changes might you see in psoriasis
pitting, oncholysis, subungual hyperkeratosis
how will lichen planus present
itchy, purple plaque and papules on wrists/arms
mouth changes in lichen planus
wickham striae - white lines
cell cahnges seen in lichen planus
hyperkeratosis with saw toothing of the rete ridges and basal cell deg
how will erythema multiforme present
annular target lesions on hands/feet
what are the main causes of erythema multiforme
inf - hsv/mycoplasma
drugs - SNAPP (sulphonamides, NSAIDs, allopurinol, penecillin, phenytoin)
how will dermatitis herpetiformis present
itchy vesicles on the extensor surfaces of elbow/butt
what condition is derm herpetiformis asso with
coeliac disease
what mediated derm. herpetiformis
IgA - binds to basement memb -> subepidermal bulla
what is the histology of derm. herpetiformis
microabsesses, subepidermal bulla, IgA deposits
what is the path of bullous pemphigoid
IgG Abs bind to hemidesmosomes of BM -> deep bulla
how will bullous pemphigoid present
large, deep bulla on an erythematous base
on the forearms/groin of elderly
histopath of bullous pemphigoid
subepidermal bulla
linear IgG deposits
what is the path of pemphigus vulgaris
IgG Abs bind to hemidesmosomal prot -> superficial bulla
how will pemphigus vulgaris present
bulla are intraepidermal (easily rupture)
found on skin and mucous memb
what is the histo finding in pemphigus vulgaris
intercellular IgG deposits
how will suborrhoeic keratosis present
waxy, stuck on plaques
how will bowes disease present
flat, red, scaly patches on sun exposed areas
basement memb intact
what are the risks of bowens disease
premalig for SCC
when does bowens disease become SCC
once the cancer invades the basement memb
how will a basal cell c present
pearly surface with rolled edges
telegiectasia
where will Basal cell C metastasize to
does no metastasize
how will a malig melanoma present
irreg border, variable pigment, itchy, bleeding, growing
how will a malig melanoma grow
radial then vertical growth [hase
how is a malig melanoma staged
breslow thickness
