Skin pathology: Inflammatory dermatoses

Question 1

function of skin

Answer 1

barrier against environmental insults and fluid loss

Question 2

what composes the skin

Answer 2

epidermis and dermis

Question 3

Epidermis has what in it, and what are the layers

Answer 3

keratinocytes

1. statum basalis
2. stratum spinosum
3. stratum granulosum
4. statum corneum

Question 4

characterize Stratum basalis

Answer 4

regenerative (stem cell) layer

Question 5

characterize Stratum spinosum

Answer 5

desmosomes between keratinocytes

Question 6

characterize Stratum granulosum

Answer 6

granules in keratinocytes

Question 7

characterize Stratum corneum

Answer 7

keratin in anucleate cells

Question 8

what is located in the dermis

Answer 8

connective tissue
nerve endings
blood and lymphatic vessels
adnexal structures

Question 9

what are adnexal structures

Answer 9

hair shafts
sweat glands
sebaceous glands

Question 10

What is atopic (eczematous dermatitis)

Answer 10

pruritic, erythematous, oozing rash with vesicles and edema

Question 11

where does atopic (eczematous) dermatitis usually occur

Answer 11

face and flexor surfaces

Question 12

what type of hypersensitivity is atopic (eczematous) dermatitis

Answer 12

Type I hypersensitivity

Question 13

what is atopic (eczematous) dermatitis associated with

Answer 13

asthma

allergic rhinitis

Question 14

what is conact dermatitis

Answer 14

pruritic, erythematous, oozing rash with vesicles and edema

Question 15

what can cause contact dermatitis

Answer 15

exposure to allergens:

1. Poison Ivy and Nickel Jewelry ( type IV)
2. irritant chemicals (e.g., detergents)
3. drugs (e.g., penicillin)

Question 16

how is contact dermatitis treated

Answer 16

• removal of offending agent

- topical glucocorticoids, if needed

Question 17

what is acne vulgaris

Answer 17

• comedones (whiteheads and blackheads)
• pustules ( pimples)
• nodules

Question 18

who usually gets acne vulgaris

Answer 18

extremely common

-especially adolescents

Question 19

what causes acne vulgaris

Answer 19

chronic inflammation of hair follicles and associated sebaceous glands

Question 20

what are 2 causes of acne vulgaris

Answer 20

1. hormone-associated

2. Propionibacterium acnes

Question 21

Propionibacterium acne causes acne how?

Answer 21

1. produces lipases that break down sebum
2. releasing proinflammatory fatty acids
   - results in pustule or nodule formation

Question 22

how does hormone -associated acne vulgaris cause acne

Answer 22

1. increases in sebum production: sebaceous glands have androgen receptors
2. excess keratin production: blocks follicles

forming comedones

Question 23

What is the treatment for acne vulgaris

Answer 23

• Benzoyl peroxide ( antimicrobial)

- vitamin A derivatives ( isotretinoin) - reduces keratin production

Question 24

what is psoriasis

Answer 24

well-circumscribed, salmon-colored plaques with silvery scale

Question 25

where does psoriasis usually occur

Answer 25

extensor surfaces and saclp

Question 26

what is physical exam finding for psoriasis

Answer 26

pitting of nails

Question 27

what causes psoriasis

Answer 27

excessive keratinocyte proliferation

Question 28

what are 2 etiologies of psoriasis

Answer 28

1. associated with HLA-C | 2. Lesions often arise in areas of trauma ( environmental trigger)

Question 29

Name 4 things that show up in histo fo psoriasis

Answer 29

1. acanthosis 2. Parakeratosis 3. Munro microabscesses 4. thinning of epidermis above elongated dermal papillae

Question 30

acanthosis

Answer 30

epidermal hyperplasia

Question 31

parakeratosis

Answer 31

hyperkeratosis with retention of keratinocyte nuclei in stratum corneum

Question 32

munro microabscesses

Answer 32

collections of neutrophils in stratum corneum

Question 33

what is Auspitz sign

Answer 33

thinning of epidermis --> bleeding when scale is picked off | -psoriasis

Question 34

treatment for psoriasis

Answer 34

corticosteroids UV light with psoralen immune-modulating therapy

Question 35

what is lichen planus

Answer 35

pruritic, planar, polygonal, purple papules, often with reticular white lines on their surface ( Wickham striae)

Question 36

common location of lichen planus

Answer 36

wrists, elbows, oral mucosa

Question 37

oral involvement for lichen planus manifests as

Answer 37

Wichman striae

Question 38

etiology of lichen planus

Answer 38

unknown | - associated with chronic Hep C virus infection

Question 39

What is pemphigus vulgaris

Answer 39

autoimmune destruction of desmosomes between keratinocytes

Question 40

what causes pemphigus vulgaris

Answer 40

IgG antibody against desmoglein | Type II hypersensitivity

Question 41

how does pemphigus vulgaris present on the skin

Answer 41

skin and oral mucosa bullae

Question 42

what is the histo for pemphigus vulgaris

Answer 42

- acantholysis (separation) of stratum spinosum keratinocytes ( normally connected by desmosomes) --> suprabasal blisters - basal layer of cells remain attached to basement membrane via hemidesmosomes ('tombstone' appearance)

Question 43

what is Nikolsky sign for pemphigus vulgaris

Answer 43

thin-walled bullae rupture easily | -leading to shallow erosions with dried crust