Epidermal & Dermal Response to Injury

Question 1

why should a gross description of a lesion be submitted with a biopsy

Answer 1

skin biopsies are small (usually 6 mm punch biopsies)

requires adequate description of the gross appearance to achieve a final diagnosis

Question 2

what are the two main steps of describing dermatologic lesions

Answer 2

1. patterns - cell arrangement
2. subcategories

Question 3

what are the subcategories to describe patterns

Answer 3

• character of cell infiltrate
• superficial vs deep
• primary spongiosis
• necrotizing
• ulcerative
• hyperplastic

Question 4

perivascular dermatitis

Answer 4

inflammation surrounding the vessels of the dermis

Question 5

how common and how diagnostic is perivascular dermatitis

Answer 5

very common - ALL dermatitis starts as perivascular because cells extravasate from vessels

LEAST diagnostic pattern

Question 6

what epidermal changes are seen in perivascular dermatitis

Answer 6

• pruritus
• inflammation
• scratching/licking

Question 7

acute histologic lesions of perivascular dermatitis

Answer 7

• spongiosis
• parakeratosis
• hypogranulosis

Question 8

chronic histologic lesions of perivascular dermatitis

Answer 8

• compact hyperkeratosis
• hypergranulosis

Question 9

what does the depth of perivascular dermatitis tell you

Answer 9

superficial only: indicates an outside –> in process

superficial + deep: indicates an inside –> out process

Question 10

what does type of cell infiltrate tell you about perivascular dermatitis

Answer 10

chronicity

cell type changes over time

Question 11

what are specific features associated with perivascular dermatitis

Answer 11

• keratinocyte swelling (intracellular edema)
• diffuse superficial epidermal lysis
• diffuse parakeratosis
• keratinocyte apoptosis

Question 12

what disease process is most consistent with keratinocyte swelling

Answer 12

viral infection

Question 13

what disease process is most consistent with parakeratosis

Answer 13

metabolic process

Question 14

cytotoxic interface dermatitis

Answer 14

single cell necrosis or apoptosis of keratinocytes

causes keratinocytes to become VACUOLATED

Question 15

what are etiologies for cytotoxic interface dermatitis

Answer 15

• autoimmune
• immune-mediated
• viral
• ischemic

Question 16

cell-rich interface

Answer 16

lichenoid inflammation associated with single cell necrosis
- subepidermal band of inflammatory cells

Question 17

cell-poor interface

Answer 17

minimal to mild perivascular inflammation

Question 18

pigmentary incontinence

Answer 18

damage to keratinocytes leading to “drop out” of melanin that gets phagocytized by dermal macrophages

causes leukoderma and leukotrichia

Question 19

subepidermal clefting

Answer 19

basal cell damage leading to BMZ failure and dermal-epidermal separation

causes ulceration

Question 20

vasculitis

Answer 20

inflammation of the blood vessels (arteries, veins, small vessels)

Question 21

what causes vasculitis

Answer 21

infectious
immune mediated

Question 22

signs of acute vasculitis

Answer 22

erythema
ecchymosis
hemorrhagic macules
palpable purpura
superficial ulcers
necrosis
no blanching on diascopy

Question 23

diascopy

Answer 23

pressing a glass slide against redness to determine if true color change or vasodilation

Question 24

histology of vasculitis

Answer 24

inflammatory cells migrating through vessel wall with NECROSIS of the wall

target of cell attack is the vascular wall

Question 25

cell rich vasculitis

Answer 25

intact and degenerate inflammatory cells within wall various degrees of degenerative change

Question 26

cell poor vasculitis

Answer 26

degenerative changes of the vascular walls lack of inflammation

Question 27

intraepidermal vesicular/pustular dermatitis

Answer 27

accumulation of fluid (vesicles) or fluid + inflammatory cells (pustules) within the epidermal layer

Question 28

what do vesicles and pustules turn into

Answer 28

rupture to form erosions and crusting

Question 29

erosions

Answer 29

loss of the epidermis with intact basal cell layer

Question 30

crusts

Answer 30

degenerated cells + serum + WBCs, RBCs

Question 31

what lesions would you want to sample the edge for biopsy

Answer 31

vesicles/pustules erosions/ulcers

Question 32

subepidermal vesicular/pustular dermatitis

Answer 32

accumulation of fluid or fluid + inflammatory cells below the epidermis (in BMZ)

Question 33

what lesion occurs from sub epidermal dermatitis

Answer 33

ulceration due to splitting at the BMZ

Question 34

what can lead to subepidermal dermatitis as a secondary lesion

Answer 34

1. cytotoxic interface dermatitis 2. neutrophilic inflammation 3. hypoxia 4. steroid drugs

Question 35

folliculitis

Answer 35

inflammation of the hair follicle

Question 36

perifolliculitis

Answer 36

perifollicular perivascular/nodular dermatitis

Question 37

furunculosis

Answer 37

ruptured hair follicle leading to free keratin and hair shaft in the dermis elicits an immune response to foreign body in dermis

Question 38

perforating folliculitis

Answer 38

superficial rupture of hair follicles

Question 39

luminal folliculitis

Answer 39

inflammatory cells that cross the follicular epithelium and accumulate in the lumen of the follicle

Question 40

what causes luminal folliculitis

Answer 40

infectious (bacterial, fungi, demodex, pelodera)

Question 41

mural folliculitis

Answer 41

inflammatory cells migrate into the follicular epithelium (NOT the lumen)

Question 42

what causes mural folliculitis

Answer 42

infectious auto-immune immune-mediated

Question 43

bulbitis

Answer 43

inflammation of the hair bulb and deep hair follicle leads to alopecia with no other superficial lesions due to no hair follicle

Question 44

what causes bulbitis

Answer 44

autoimmune

Question 45

nodular to diffuse dermatitis

Answer 45

inflammation of the dermis in nodular aggregates or generalized/diffuse distribution

Question 46

what causes nodular/diffuse dermatitis

Answer 46

neoplasia vs inflammatory (infectious vs noninfectious)

Question 47

panniculitis

Answer 47

inflammation of the subcutis that occurs as an extension of dermatitis (dermal inflammation)

Question 48

what causes panniculitis

Answer 48

infectious metabolic immune mediated idiopathic