Skin 1 - Inflammatory Dermatoses

Question 1

What is the function of skin?

Answer 1

It is a barrier against environmental insults and fluid loss

Question 2

What is skin composed of?

Answer 2

an epidermis and dermis

Question 3

What is the epidermis comprised of?

Answer 3

keratinocytes and has four layers

Question 4

What are the layers of the epidermis?

Answer 4

1) Stratum basalis 2) Stratum spinosum 3) Stratum granulosum 4) Stratum corneum

Question 5

What is the stratum basalis?

Answer 5

regenerative (stem cell) layer

Question 6

What is the stratum spinosum?

Answer 6

Its characterized by desmosomes between keratinocytes

Question 7

What is the stratum granulosum?

Answer 7

It is characterized by granules in keratinocytes

Question 8

What is the stratum corneum?

Answer 8

It is characterized by keratin in anucleate cells

Question 9

What does the dermis consist of?

Answer 9

connective tissue, nerve endings, blood and lymphatic vessels, and adnexal structures (e.g., hair shafts, sweat glands, and sebaceous glands)

Question 10

What are the inflammatory dermatoses?

Answer 10

1) atopic (eczematous) dermatitis 2) contact dermatitis 3) acne vulgaris 4) psoriasis 5) Lichen Planus

Question 11

What is atopic (eczematous) dermatitis?

Answer 11

Pruritic, erythematous, oozing rash with vesicles and edema; often involves the face and flexor surfaces

Question 12

What are flexor surfaces?

Answer 12

Elbow, wrists and knees

Question 13

What is type 1 hypersensitivity reaction associated with?

Answer 13

asthma and allergic rhinitis

Question 14

What is contact dermatitis?

Answer 14

Pruritic, erythematous, oozing rash with vesicles and edema

Question 15

When does contact dermatitis arise?

Answer 15

upon exposure to allergens

Question 16

What are the allergens for contact dermatitis?

Answer 16

1) Poison ivy and nickel jewelry (type IV hypersensitivity) 2) Irritant chemicals (e.g., detergents) 3) Drugs (e.g., penicillin)

Question 17

What is the treatment for contact dermatitis?

Answer 17

It involves removal of the offending agent and topical glucocorticoids, if needed.

Question 18

What is acne vulgaris?

Answer 18

Comedones (whiteheads and blackheads), pustules (pimples), and nodules; extremely common, especially in adolescents

Question 19

What is acne vulgaris due to?

Answer 19

chronic inflammation of hair follicles and associated sebaceous glands

Question 20

In acne vulgaris, how are comedones formed?

Answer 20

There is hormone-associated increase in sebum production (sebaceous glands have androgen receptors) and excess keratin production block follicles

Question 21

What are propionibacterium acnes?

Answer 21

It is infection that produces lipases that break down sebum, releasing proinflammatory fatty acids; results in pustule or nodule formation

Question 22

What is the treatment for acne vulgaris?

Answer 22

Treatment includes benzoyl peroxide (antimicrobial) and vitamin A derivatives (e.g., isotretinoin), which reduce keratin production.

Question 23

What is psoriasis?

Answer 23

Well-circumscribed, salmon-colored plaques with silvery scale, usually on extensor surfaces and the scalp; pitting of nails may also be present.

Question 24

What is psoriasis due to?

Answer 24

excessive keratinocyte proliferation

Question 25

What is the etiology for psoriasis?

Answer 25

Possible autoimmune etiology

Question 26

What is psoriasis associated with?

Answer 26

HLA-C

Question 27

For psoriasis, what happens if there is an environmental trigger?

Answer 27

lesions often arise in areas of trauma (environmental trigger)

Question 28

What does the histology for psoriasis show?

Answer 28

1) Acanthosis (epidermal hyperplasia) 2) Parakeratosis 3) Collections of neutrophils in the stratum corneum (Munro microabscesses) 4) Thinning of the epidermis above elongated dermal papillae; results in bleeding when scale is picked off (Auspitz sign)

Question 29

What is parakeratosis?

Answer 29

hyperkeratosis with retention of keratinocyte nuclei in the stratum comeum

Question 30

What is the treatment for psoriasis?

Answer 30

it involves corticosteroids, UV light with psoralen, or immune-modulating therapy.

Question 31

What is lichen planus?

Answer 31

Pruritic, planar, polygonal, purple papules often with reticular white lines on their surface (Wickham striae); commonly involves wrists, elbows, and oral mucosa

Question 32

What does lichen planus commonly involve?

Answer 32

Wrists, elbows and oral mucosa

Question 33

What does oral involvement of lichen planus manifest as?

Answer 33

Wickham striae

Question 34

What does histology for lichen planus show?

Answer 34

inflammation of the dermal-epidermal junction with a saw-tooth appearance

Question 35

What is the etiology for lichen planus?

Answer 35

Etiology is unknown

Question 36

What is lichen planus associated with?

Answer 36

chronic hepatitis C virus infection