Skin Flashcards
Define Macule or patch
Spot,flat lesion, red/pink
Define papule or nodule
a large, more raised macule/patch
Define plaque
Raised flat large patch
Define pustule
Raised and filled with pus
Define Scale
scaly skin, from layers of keratin sloughing off
Define vesicle and bulla
Vesicle is a blister, bulla is a large blister
Define Acanthosis
thickening of epidermal layer
Define hyperkeratosis
hyperplasia of stratum coreum
Define parakeratosis
cells retain nuclei in stratum corneum and the other layers
Define spongiosis
Intercellular edema in the epidermis
Explain and compare the pathophysiology of..
acute inflammatory dermatoses – urticaria,
acute eczematous dermatitis (limit this to allergic contact dermatitis),
and erythema multiforme
Just in general terms…
(think what causes it, rate, etc.)
hives– present as erythematous, edematous, often circular
plaques (wheals), pruritic (itchy)
These appear FAST, from allergens
**DERMIS ONLY
(ex: poison ivy, Ni)
* *THIS IS DELAYED TYPE 4/T CELLS
* *BLISTERING
– reaction to infections (herpes simplex,
pneumonia) and sometimes to drugs
Explain and compare the pathophysiology of..
acute inflammatory dermatoses – urticaria,
acute eczematous dermatitis (limit this to allergic contact dermatitis),
and erythema multiforme
Type of hypersensativity
is Type 1-Fast rxns which involve histamine and mast cells/dilated vessels and are superficial
is Type 4-DELAYED (2-4 days): T cell involvement where Th recruit macrophages and CD8 killers –> apoptosis which creates a blister forming space
EM is Type 4- (3-5 days)
Type 1 Sensitivity and cells?
Rate?
Mast cells release histamine –> creates immediate hypersensitivity
reaction (normally an allergy), involves vasodilation and is FAST; ONLY Epidermis
Delayed (Type IV) hypersensitivity reaction and cells?
Rate?
T-lymphocytes (T-cells):
i. Th (CD4) recruit other immune cells like macrophages –> inflammation
ii. Tc (CD8) cause target cells to undergo apoptosis
This is DELAYED
Explain and compare the pathophysiology of
acute inflammatory dermatoses – urticaria,
acute eczematous dermatitis (limit this to allergic contact dermatitis),
and erythema multiforme.
c. Appearance and type of skin lesion (gross level) –
urticaria: hives – present as erythematous, edematous, often circular
plaques (WHEALS), pruritic (itchy)-FAST
Acute eczematous dermatitis- If fluid continues to enter epidermis –> BLISTER
(vesicles/bulla or spongiosis)
Erythema multiforme-
HALLMARK TARGET
*These can burst
a. Bright red outer ring
b. Paler, raised area (edema)
c. Dusky or dark red central area with blister or crust
d. Appear over 3-5 days and resolve in 2 weeks
Erthythema multiforme minor vs EM major
minor skin
major skin with mucousal involvement
Appearance of EM (4 hallmarks)
**ONE BIG ONE
**TARGET LESION
a. Bright red outer ring
b. Paler, raised area (edema)
c. Dusky or dark red central area with blister or crust
d. Appear over 3-5 days and resolve in 2 weeks
Acute eczematous dermatitis appearance
If fluid continues to enter epidermis –> blister
(vesicles/bulla).
redness, edema in outermost layers of
dermis, itchy
Urticaria appearance
hives – present as erythematous, edematous, often circular
plaques (WHEALS), pruritic (itchy)-appear in minutes
Explain and compare the pathophysiology of
acute inflammatory dermatoses – urticaria,
acute eczematous dermatitis (limit this to allergic contact dermatitis),
and erythema multiforme.
d. Involvement of the oral mucosa
Seems to be that of these three acute hypersensativity rxns only Erythema multiforme involves
the oral mucosa
EM Major: with mucosal involvement
a. Mucosal lesions develop a few days after the skin rash
begins
b. Swelling, redness, blister formation -> breaks and
leaves painful ulcers
Disappear quickly
For chronic inflammatory dermatoses – psoriasis and lichen planus.
a. Explain involvement of T cells…
Autoimmune?
and their effect on…
basal cells, keratinocytes, the epidermis, blood vessels
T cell mediated autoimmune disease
i. Genetic and environmental factors –> antigens –> sensitized T
cells to the dermis and accumulate in the epidermis –> release
cytokines (IL 22) –> keratinocyte hyperproliferation in epidermis –>
excessive and rapid growth of epidermis… This leads to a delay in migration time from basal cells to surface and cells with retained nuclei at the surface (PARAKERATOSIS)
**does lead to DILATED, HYPERPLASTIC BLOOD VESSELS
___ is a disease of skin or mucous membrane that resembles lichen,
thought to be autoimmune but trigger is unknown
Antigen on cells in basal layer –> activation of CD8 –> KERATINOCYTE APOPTOSIS –> causes degeneration of basal layer and gives lesion a purple color, concentrated at the
epidermal-dermal interface this leads to SAW-TOOTH EPIDERMIS
Explain and compare the pathophysiology of chronic inflammatory dermatoses – psoriasis and lichen planus.
c. Appearance and type of skin and/or oral lesions (gross level) – why and how these occur?
Describe each epidermis, and what they look like grossly
-both have 2 unique things
thin area of epidermis becuase of parakeratosis
silver/white Scale…
When this scale is removed –> small bleeding = AUTZPITZ SIGN
Saw-tooth epidermis
- Pink-purple, elevated polygonal papule
- Wickham striae (white, lacelike markings)
pathophysiology of chronic inflammatory dermatoses – psoriasis and lichen planus.
d. Involvement of the oral mucosa
Psoriasis does not…
Lichen planus: wickman’s striae on tongue (white lace-like)
pathophysiology of chronic inflammatory dermatoses – psoriasis and lichen planus.
e. Possible precipitating events
2 for Psoriasis
2 for Lichen
–> –> keratinocyte hyperproliferation in epidermis –>
excessive and rapid growth of epidermis –>
–> (PARAKERTOSIS, where cells on surface have nuclei and epidermis is THIN)
—AUTZPITZ Sign
Pink-purple, elevated polygonal papule Wickman striae (white, lacelike)
pathophysiology of chronic inflammatory dermatoses – psoriasis and lichen planus.
f. What are Auspitz signs and explain why they occur?
When the formed scale is removed or peeled off, it creates small bleeds due
to not a lot of room between blood vessels and epidermis = Autzpitz Sign
This is a result of hyperplasia of keratinocytes leading to PARAKERATOSIS and a THIN EPIDERMIS
pemphigus vulgaris and foliaceus
Target proteins or antigens involved – explain why the blisters develop in the different locations (i.e. cleft position)
Anti-desmoglein IgG-lose cell to cell adhesion between keratinocytes
Desmoglein 1 is concentrated in the upper epidermis…
Desmoglein 3 is in the lower epidermis and mucous membranes
Where are lesions of pemphigus vulgaris and foliaceus found?
Vulgaris has Abs to Desmoglein 1 and 3-so it is in the upper and lower epidermis, AND mucous membranes..
Foliaceus is ONLY in the upper epidermis and Skin only because desmoglein 1-NOT oral mucosa
bullae vs vessicle
bullae is a big blister, vessicle is smaller
Skin layer of pemphigus vulgaris and foliaceus
intraepidermal and supra epidermal
Skin layer of pemphigus vulgaris and foliaceus-where does it cause cleavage and where does it stain?
____ Stains intraepidermal
It causes cleavage supra-basal
___stains in the upper epidermis and cleaves subcorneal
Explain and compare the pathophysiology of blistering (bullous) disorders –
pemphigus vulgaris and foliaceus,
bullous pemphigoid,
dermatitis herpetiformis.
a. Target proteins or antigens involved – explain why the blisters develop in the different locations (i.e. cleft position)
Vulgaris= Abs to desmoglein 1 and 3
Foliaceous= Abs to desmoglein 1
ii. More desmoglein 1 in upper part of epidermis
iii. Desmoglein 3 more concentrated in lower part of epidermis and
mucous membranes
—– targets proteins such as type XVII collagen in hemidesmosomes and BM and can affect skin and mucous membranes
Dermatitis Herpetiformis is caused by gluten and causes intact subepidermal blisters-Glutinamase
A 45-year-old male presents to his dentist with difficulty eating and drinking. Erosions on his tongue and lips are noted, which apparently started a few months ago as a small blister, but has ‘spread’. The dentist also notes areas of erosions with a few flaccid bullae on his skin. The patient states that one time, when he pressed on his skin with a sliding motion, the outer layer of skin seemed to rub off.
There is high suspicion that he has:
Pemphigus vulgaris-the skin rubs off
One reason why the lesions associated with acute eczematous dermatitis may not occur for a day or 2 after antigen exposure is because it takes a while for:
A. An allergen to bind to IgE on mast cells
B. Memory T cells to move to the site of
antigen exposure and be activated
C. IgE to be produced by plasma cells and
bind to mast cells in connective tissue
D. Langerhans cells to present antigen to a
naïve T cell in a lymph node
Probably B?
Explain and compare the pathophysiology of blistering (bullous) disorders – pemphigus vulgaris and foliaceus,
bullous pemphigoid,
dermatitis herpetiformis
f. Possible precipitating events (is it erosive? Flacid?)
pemphigus vulgaris: skin erosion and broken blisters
foliaceus: less erosive.. tends to break
——–: hard to break blisters, can affect mucosa
——-: erode and become ulcerated
Explain and compare the pathophysiology of blistering (bullous) disorders –
dermatitis herpetiformis.
a. Target proteins or antigens involved – explain why the blisters develop in the different locations (i.e. cleft position)
Autoimmune blistering disorder responding to a gluten-free diet (celiacs)
**NOT herpes
Subepidermal blister with intact epidermis-itchy
A 44-year-old female presented to her primary care physician with a complaint of an itchy, red area on her neck. She states that she wore a new necklace for the last 2 days and then this started!
What does she have?
Allergic contact dermatitis
Explain and compare the pathophysiology of blistering (bullous) disorders –
pemphigus vulgaris and foliaceus
b. Characteristic histological features – both with H&E staining and immunofluorescence
Suprabasal acantholysis (lysed layer of
ENTIRE EPITHELIAL CELL LAYER above
basal membrane)
antibodies to desmoglein 1; also has SUBCORNEAL-ONLY UPPER EPIDERMIS
Explain and compare the pathophysiology of blistering (bullous) disorders –
bullous pemphigoid
b. Characteristic histological features – both with H&E staining and immunofluorescence
Subepidermal blister, very full and thick epidermis
Linear in Subepidermal basement membrane
Explain and compare the pathophysiology of blistering (bullous) disorders –
dermatitis herpetiformis.
b. Characteristic histological features – both with H&E staining and immunofluorescence
Subepidermal….
intact epidermis
– blister with intact epidermis
iii. Grouped intact or eroded pustules and vacuoles
A 25-year-old male with a nut allergy accidentally eats a cookie with nuts. About 15 minutes later he breaks out in an itchy rash.
Erythematous, edematous, often circular plaques (Wheals)
Pruritic
What does he have?
Uticaria
A pathologists is looking at a skin biopsy and the first thing they note is hyperkeratosis. When starting to build their list of differential diagnoses, they are most likely considering a(n):
A. Acute inflammatory dermatosis B. Chronic inflammatory dermatosis C. Blistering disorder
B. Chronic inflammatory
A 25-year-old male is stung by a bee in his hand. Within about 10 minutes, the area that was stung is beginning to get red and swollen. Which of the following would be most useful in reversing or treating his symptoms? A. Blocking histamine receptors B. Blocking TNF receptors C. Inhibiting T cell activation D. Preventing IgE production E. Preventing mast cell degranulation
A. Blocking histamine receptors
Has uticaria
Explain and compare the pathophysiology of blistering (bullous) disorders –
pemphigus vulgaris and foliaceus
d. Type of blister – how erosive and their tendency to break (flaccid or tense).
Pemphigus (vulgaris and foliaceous)
i. Vulgaris: antibodies to desmoglein 1 and 3
Blister tends to be more erosive and flacid, can break-SCRAPES OFF
Foliaceous:
Less erosive, tend to break also
Explain and compare the pathophysiology of blistering (bullous) disorders –
bullous pemphigoid
d. Type of blister – how erosive and their tendency to break (flaccid or tense).
More erosive, difficult to break-THICK EPIDERMAL LAYER
Explain and compare the pathophysiology of blistering (bullous) disorders –
dermatitis herpetiformis.
d. Type of blister – how erosive and their tendency to break (flaccid or tense).
More erosive, tends to break/ulcerate
Explain and compare the pathophysiology of blistering (bullous) disorders –
pemphigus vulgaris and foliaceus
c. Appearance and type of skin and/or oral lesions (gross level)
Vulgaris:
blister that scrapes off and can be in mouth
Foliaceus: cutaneous blister, less likely to scrap off
Explain and compare the pathophysiology of blistering (bullous) disorders –
bullous pemphigoid
c. Appearance and type of skin and/or oral lesions (gross level)
Subepidermal blister, very full and thick epidermis, harder for blister
to break
1. Tense bullae
Explain and compare the pathophysiology of blistering (bullous) disorders –
dermatitis herpetiformis
c. Appearance and type of skin and/or oral lesions (gross level)
Subepidermal blister with intact epidermis
iii. Grouped intact or eroded pustules and vacuoles – very itchy, erode
- —> and become ulceration
Explain and compare the pathophysiology of blistering (bullous) disorders –
pemphigus vulgaris
and foliaceus
e. Involvement of the oral mucosa or mucous membranes
Vulgaris=desmoglein 1 and 3 so it does involve mucous membranes
Foliaceus: Desmoglein 1 only, so NO MUCOSAL involvement just upper epidermis
Explain and compare the pathophysiology of blistering (bullous) disorders –
bullous pemphigoid
e. Involvement of the oral mucosa or mucous membranes
Yes-via effecting hemidesmosomes
Explain and compare the pathophysiology of blistering (bullous) disorders –
dermatitis herpetiformis
e. Involvement of the oral mucosa or mucous membranes
Subepidermal blister which does not have mucosal involvement
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
a. Involvement of UV radiation or sun damage
Cause/Risk Factors?
Dysplasia?
—- cause unkown, age related (over 50), many have a mutation in FGFR3 –> excessive production of keratin
—Sun, occurs on balding scalp, lateral neck,
distal upper or lower extremities
i. Sun related: UV –> DNA damage –> TP53 mutation –> proliferation of basal cells –> interpithelial DYSPLASIA
Define dysplasia
Dysplasia is atypical cells in the epithelium with signs of malignant cells including the 5 keys:
(hyperchromatic nuclei, irregular nuclear membranes, increased nuclear to cytoplasmic ratio, mitotic figures, architectural anarchy)
This is NOT malignancy and is confined to epithelium, no metaplasia and well differentiated
Where does dysplasia tend to occur/confined to where?
confined to the epithelium
What are some of the characteristic cellular features of dysplasia?
(the 5)
The 5 signs…
hyperchromatic
nuclei, irregular nuclear membrane, increased nuclear to cytoplasmic ratio, mitotic figures, architectural anarchy
Cells do not change cell type, cells have some atypical cytology and are not
well differentiated
Differentiate between dysplasia, malignancy and metaplasia
Dysplasia cells do not metastasize… BUT they can lead to Malignant cells which do metastasize…
Dysplasia cells are not metastatic (they do not change to different types of cells)
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis
Mutations involved??
- – cause unkown, age-related (over 50),
- **many have a mutation in FGFR3 –> excessive production of keratin
: occurs on balding scalp, lateral neck, distal upper or lower extremities
i. Sun related: UV –> DNA damage –> TP53 mutation –> proliferation of basal cells –> interpithelial dysplasia
- Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis (3 things here)
d. Characteristic histological features – why and how these occur.
Histological features
- Acanthosis: diffuse thickening of epidermal layer
- HORN CYSTS – filled with keratin
- No rete ridges
**Result of excess keratin production
- Explain and compare the pathology of benign and premalignant epithelial lesions –
actinic keratosis (4)
d. Characteristic histological features – why and how these occur.
Histological features
1. Partial thickness dysplasia on bottom half of epidermis
2. Hyperchromasia (dark nuclei)
3. Varied nuclei and cell shape with loss of orientation
(pleomorphism)
4. Hyperkeratosis and parakeratosis
- Explain and compare the pathology of benign and premalignant epithelial lesions –
and actinic keratosis (2)
e. Appearance and type of skin lesion (gross level) – why and how these occur.
On balding scalp, lateral neck, distal upper or lower extremities…
Gross morphology
1. Zone of redness (erythematous macule or patch)
- Rough/scaly (hyperkeratotic surface)
- Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
f. Progression to skin cancer?
Causes scaly-keratinized skin but does not seem to progress to cancer
Can progress to….
squamous cell carcinoma in situ –> tends to grow slowly enlarging over the course of years and asymptomatic
OR SCC invasive which invades the dermis
Compare actinic keratosis and squamous cell carcinoma in situ.
a. Which is the precursor lesion?
b. Histological and gross pathological differences.
– partial thickness epidermal dysplasia
– full thickness epidermal dysplasia but has not penetrated basement
membrane
Invasive SCC – full thickness epidermal dysplasia and has penetrated basement membrane
to involve dermis
Oral SCC vs cutaneous?
Oral is more agressive
Oral SCC commonly found where in mouth
Floor of mouth and lateral or ventral tongue
Oral SCC histo
Histological features
- Full thickness dysplasia
- Carcinoma invaded dermis (should be mainly collagen) –> nuclear crowding and disorganization
- Keratin pearls: cells that make arrangements of keratin into swirls
Compare the difference between actinic keratosis, squamous cell carcinoma in situ, and invasive squamous cell carcinoma – location of dysplasia and whether or not it has penetrated the basement membrane
Actinic keratosis – partial thickness epidermal dysplasia
SCC in situ – full thickness epidermal dysplasia but has not penetrated basement
membrane
Invasive SCC – full thickness epidermal dysplasia and has penetrated basement membrane
to involve dermis
Explain and compare the pathophysiology of
acute inflammatory dermatoses – urticaria,
acute eczematous dermatitis (limit this to allergic contact dermatitis),
and erythema multiforme.
c. – why or how these occur?
Uriticaria: Caused by pollen, food, drugs, venom….
Just dilated vessels in the dermis really
Acute Eczematous dermatitis: apoptosis of keratinocytes caused by CD8 cells causes space between epidermis which can fill up and blister (spongiosis, bullae, vesicles)
Erythema multiforme is triggered by infectious diseases… These form similar to acute eczematous but these can burst.. :(
Explain and compare the pathophysiology of chronic inflammatory dermatoses – psoriasis.
Migration time from basal layer to surface changed at all?
Blood vessels involved?
- Migration time from basal layer to surface increases to about
4-7 days –> retained nuclei at skin surface because no time for
keratinocytes (parakeratosis) - Dilated, hyperplastic blood vessels
