Skin

Question 1

Epidermis layers: superficial to deep

Answer 1

corneum
Granulosum
spinosum
basalis

Question 2

Stem cell layer of epidermis

Answer 2

Basalis

Question 3

Layer with desmosomes

Answer 3

Spinosum

Question 4

Granules in keratinocytes

Answer 4

Granulosum

Question 5

Keratin in anucleate cells

Answer 5

Corneum

Question 6

Structures found in dermis

Answer 6

CT, nerve endings, blood and lymphatic vessels, adnexal structures (hair shafts, sweat glands, sebaceous glands)

Question 7

Atopic Dermatitis

Answer 7

Eczema
Pruritic, erythematous, oozing rash with vesicles and edema
Face/flexor surfaces
Type 1 hypersensitivity

Question 8

Atopic Dermatitis associated with

Answer 8

Asthma and allergic rhinitis

Question 9

Contact dermatitis

Answer 9

Pruritis, erythematous, oozing rash with vesicles and edema
Allergen exposure: Poison ivy/nickel jewelry (T4H), Irritant chemicals, Drugs
TX: remove allergen & topical glucocorticoids

Question 10

Acne Vulgaris

Answer 10

Comedones (white & blackheads)
Pustules (pimples)
Nodules (scars)

Chronic inflammation of hair follicles and sebaceous glands

P acnes - lipases break down sebum - result in proinflammatory FA

TX: benzoyl peroxide & VIT A Derivatives

Question 11

Psoriasis

Answer 11

Salmon-colored plaques w/ silvery scale
Extensor surfaces & scalp
PItting of nails
Excessive keratinocyte proliferation

AI: HLA-C
In areas of trauma

Question 12

Psoriasis HLA association

Answer 12

HLA-C

Question 13

Histology of psoriasis

Answer 13

1. Acanthosis (epidermal hyperplasia)
2. Parakeratosis (hyperkeratosis w/ retention of keratinocyte nuclei in corneum - results in silvery scale)
3. Neutrophils in corneum (Muncro microabscesses)
4. Thinning of epidermis above elongated dermal papillae (Auspitz sign)

Question 14

TX psoriasis

Answer 14

Corticosteroids, PUVA, immune-modulating therapy

Question 15

Lichen Planus

Answer 15

4 P’s
Pruritic, planar, polygonal, purple papules
Wrists, elbows, mucosa (Wickham striae - reticular white lines on surface)

Saw tooth appearance of inflammation at dermal/epidermal junction

Associated w/ chronic Hep C

Question 16

Pemphigus vulgaris

Answer 16

AI destruction of desmosomes in spinosum
IgG against desmoglein (T1H0
Skin and oral bullae

Acanthyolysis of spinosum - suprabasal blisters
Thin walled/rupture easily (Nikolsky sign)
IF: IgG surrounding keratinocytes: Fish net pattern

Question 17

Bullous pemphigus

Answer 17

AI of hemidesmosomes between basal cells and BM
IgG against hemidesmosomes (BP180) of BM
Skin blisters - mucosa spared
Basal cell detaches from BM - tense bullae hard to rupture

IF: linear pattern - IgG along BM

Question 18

Dermatitis Herpetiformis

Answer 18

IgA deposition at tips of dermal papillae
Pruritic pustules/bullae
Associated with celiac dz - Ab against gluten

Question 19

Erythema Multiforme

Answer 19

Hypersensitivity Rxn
Targetoid rash and bullae - targetoid d/t necrosis at center

HSV most common
Other: Mycoplasm infection, drugs, AI, malignancy

Question 20

Erythema Multiforme with oral mucosa/lip involvement and fever:

Answer 20

SJS

TEN (toxic epidermal necrolysis is severe form SJS) - diffuse sloughing of skin - adverse drug rxn

Question 21

Seborrheiic keratosis

Answer 21

Benign squamous proliferation

Question 22

Sudden onset of multiple seborrheic keratosis related to (and name of sign)

Answer 22

Sign: Leser Trelat

Suggests underlying GI carcinoma

Question 23

Acanthosis nigricans

Answer 23

Insulin resistance or gastric carcinoma

Question 24

Basal cell carcinoma

Answer 24

Most common form of cutaneous malignancy
UVB (also albinism/xeroderma pigmentosum)

Histology shows peripheral palasading nodules of basal cells

TX: excision

Question 25

Classic location BCC vs SCC

Answer 25

BCC: upper lip SCC: lower lip

Question 26

SCC

Answer 26

Keratin pearls UVB (also albinism/xeroderma pigmentosum) Additional factors: Immunosuppressive therapy, arsenic exposure, chronic inflammation TX: excision

Question 27

SCC precursor

Answer 27

Actinic keratosis - hyperkeratotic, scaly plaque, face, neck, back

Question 28

Keratoacanthoma

Answer 28

Develops rapidly/regresses spontaneously Cup shaped tumor w/ keratin debbis

Question 29

What are melanocytes derived from?

Answer 29

neural crest

Question 30

Melanin synthesis

Answer 30

Tyrosine to melanin then pass malanosomes to keratinocytes

Question 31

Freckle d/t

Answer 31

increased number of melanosomes

Question 32

Nevus

Answer 32

Benign neoplasm of melancytes Children: dermal-epidermal junction (junctional nevus) Adults - lose junctional component - results in intradermal nevus

Question 33

Variants of Melanoma

Answer 33

1. Superficial spreading - most common: early radial growth 2. Lentigo maligna melanoma - lentiginous proliferation (radial growth) 3. Nodular: early vertical growth (poor prognosis) 4. Acral lentiginous - palms/soles of dark skin people - no related to UV

Question 34

Impetigo

Answer 34

``` Superficial infection S aureus/S pyogenes Erythematous macule - progress to pustules Face Erosion & dry - honey crusted ```

Question 35

Cellulitis

Answer 35

deeper (dermal/subcutaneous) infection S aureus/S pyogenes Surgery, trauma, bug bite

Question 36

What can cellulitis progress to

Answer 36

Necrotizing fasciitis Necrosis of subcutaneous tissue d/t infection w/ anaerobic "flesh eating" bacteria Co2 production = crepitus Surgical emergency

Question 37

Staph Scalded Skin syndrome

Answer 37

Sloughing of skin w/ erythematous rash Skin loss Exfoliative toxin A & B - epidermolysis of stratum granulosum

Question 38

SSSS vs TEn

Answer 38

SSSS: stratum granulosum TEN: between dermis and epidermis

Question 39

Molluscum contagiosum virus

Answer 39

poxvirus | keratinocytes show cytoplasmic inclusions