Pathoma

Question 1

What is parakeratosis?

Answer 1

hyperkeratosis with retention of keratinocyte nuclei in stratum corneum

Question 2

What is Auspitz sign?

Answer 2

pinprick bleeding when psoriasis scales are picked off. Due to elongated dermal papillae

Question 3

What is a histological sawtooth appearance at the dermal-epidermal junction indicative of?

Answer 3

lichen planus

Question 4

What does tombstone appearance refer to?

Answer 4

Pemphigus vulgaris. When basal layer cells remain attached to basement membrane via hemidesmosomes but desmosomes are destroyed so rest stratum spinosum separates. Leaves basal cells that look like tombstones

Question 5

Describe pathology of Pemphigus Vulgaris

Answer 5

IgG antibody against desmoglein (type II hypersensitivity). Then acantholysis (separation) of stratum spinosum keratinocytes occurs and leave behind tombstome appearance of basal layer on basement membrane.

Question 6

Which blisters are more likely to rupture: those of pemphigus vulgarus or bullous pemphigoid?

Answer 6

Pemphigus vulgaris. The bullae are thin walled and rupture easily leading to shallow erosions and dried crust

Question 7

Which attachment proteins are targeted in Bullous pemphigoid?

Answer 7

hemidesmosomes

Question 8

Which attachemtn proteins are targeted in pemphigus vulgaris?

Answer 8

desmoglein (desmosomes).

Question 9

What is dermatitis herpetiformis?

Answer 9

deposition of IgA at the tips of dermal papillae. Pruritic vesicles and bullae grouped (herpetiform).

Question 10

What other disease is dermatitis herpetiformis strongly assoicated with and how can it be prevented?

Answer 10

associated with celiac disease. Resolves with gluten-free diet.

Question 11

What is erythema multiforme?

Answer 11

Hypersensitivity reaction characterized by targetoid rash and bullae. Most commonly with HSV infection or drug reactions. Can lead to Toxic epidermal necrolysis

Question 12

What is seborrheic keratosis?

Answer 12

benign squamous proliferation. Presents as raised , discolored plaques. Coin-like, waxy stuckon appearance.

Question 13

What is the Leser-Trelat sign? What does it indicate?

Answer 13

it is the sudden onset of multiple seborrheic keratoses. Suggests carcinoma of the GI tract

Question 14

What is aconthosis nigricans? What is it associated with?

Answer 14

Epidermal hyperplasia and hyperpigmentation of axilla and or groin. Associated with insulin resistance

Question 15

What is actinic keratosis?

Answer 15

precursor lesion of squamous cell carcinoma

Question 16

What is keratoacanthoma?

Answer 16

well differentiated SCC that presents as a cub shaped tumor filled with deratin debris

Question 17

What is vitiligo?

Answer 17

localized loss of skin pigmentation due to autoimmune destruction of melanocytes

Question 18

What is albinism?

Answer 18

congenital lack of pigmentation due to enzyme defect (usually tyrosinase) which impairs melanin production

Question 19

What is increased in freckles?

Answer 19

melanosomes. NOT melanocytes

Question 20

What is impetigo?

Answer 20

superficial skin infection

Question 21

What is cellulitis?

Answer 21

deeper (dermal and subcu) infection. Can profress to necrotizing fasciitis

Question 22

What is scalded skin syndrome?

Answer 22

sloughing of skin with erythematous rash and fever. Significant skin loss. Caused by staph aureus. A and B toxins cause epidermolysis of stratum granulosum.

Question 23

How is scalded skin syndrome differentiated from Toxic epidermal necrolysis?

Answer 23

the level of skin separation. TEN occurs at dermal-epidermal junction. SSS occurs at stratum granulosum.

Question 24

What is a verruca?

Answer 24

wart.

Question 25

What is molluscum contagiosum?

Answer 25

firm, pink, umbilicated papules due to poxvirus