Skin pathology

Question 1

What part of the skin is the epidermis?

Answer 1

The thin outer portion of the skin, important for the protective function of the skin

Question 2

What part of the skin is the dermis?

Answer 2

The thicker inner portion, the connective tissue layer- important for sensation, protection and thermoregulation

Question 3

What part of the skin is the hypodermis?

Answer 3

Part of the skin underneath the dermis and merged with it

Question 4

What kind of tissue do you find in the hypodermis?

Answer 4

Mainly adipose tissue and sweat glands

Question 5

What are the 5 layers of the epidermis?

Answer 5

• Stratum basale
• Stratum spinosum
• Startum granulosum
• Startum lucidum
• Stratum corneum

Question 6

What are the 3 ways cells can adhere to each other in the skin?

Answer 6

• Using hemidesmosones
• Using desmosones
• The basement membrane mediates attachment of the epidermis to the underlying dermis

Question 7

What is a pilosebaceous unit?

Answer 7

Collective name for the hair follicle, hair shaft and sebaceous gland

Question 8

What is the name for increased thickness of the stratum spinosum?

Answer 8

Acanthosis

Question 9

What is lichenification?

Answer 9

Rough thickened epiderms with acentuation of skin creases caused by marked acanthosis

Question 10

What can cause Lichenification?

Answer 10

Persistent rubbing, scratching or irritation (chronic dermatitis)

Question 11

What is hyperkeratosis?

Answer 11

Increased thickness of the stratum corneum, due to an abnormal amount of keratin- this is usually associated with epidermal hyperplasia

Question 12

What is orthokeratotic hyperkeratosis?

Answer 12

When the preserved keratinocytes mature

Question 13

What is parakeratotic hyperkeratosis?

Answer 13

Nuclei are retained as a sign of delayed keratinocyte maturation

Question 13

What is the definition of a callus?

Answer 13

• thick, firm hyperkeratotic hairless plaque with increased skin folds

Question 13

What is the cause of a callus?

Answer 13

trauma over a bony prominence such as an elbow, sternum or side of a digit

Question 14

What is the similarity and difference between a vesicle and bullae

Answer 14

• they are both ‘blisters’, localised collections of fluid within or beneath the epidermis, elevated fluid-filled lesions differented by size
• Vesicles are less than one cm in diameter, Bulla are more than 1cm in diameter

Question 15

What causes vesicles/ bullae?

Answer 15

Burns, Viral infections, immune-mediated diseases

Question 16

What is the definition of a pustule?

Answer 16

• Elevated, pus-filled vesicle usually caused by bacterial infections

Question 17

What is the definition of an erosion?

Answer 17

Partial-thickness loss of epidermis that results in a shallow, moist depression
the basement membrane remains intact

Question 18

What causes an erosion?

Answer 18

it is secondary to a vesicle or pustule rupture/ surface trauma

Question 19

What is the definition of a dried exudate?

Answer 19

fluid, blood, pustular debris or scales left behind on the skin surface

Question 20

What causes crust?

Answer 20

Often the end result of loss of integrity of the epidermis

Question 21

What is the definition of an ulcer?

Answer 21

Full-thickness loss of epidermis and the basement membrane

Question 22

What is the defnition of a scar?

Answer 22

thin to thick fibrous tissue that replaces normal skin following injury or laceration to the dermis

Question 23

What is epidermal hyperplasia?

Answer 23

Increased numbers of keratinocytes in the epidermis as a response to a variety of stimuli

Question 24

What is the definition of a blister?

Answer 24

Localised collection of fluid within or beneath the epidermis

Question 25

What is the definnition of crust?

Answer 25

* Dried exudate * Often the end results ends in the loss of the integrity of the epidermis

Question 26

Why would an erosion not bleed?

Answer 26

There are no vessels in the epidermis

Question 27

What is the definition of an ulcer?

Answer 27

Full-Thickness, loss of epidermis and the basement membrane, and at least a portion of the dermis with depression of exposed tissue- may extend into the deeper tissue

Question 28

What may cause an ulcer?

Answer 28

ischemic lesions resulting from vasculitis, indolent ulcer, feline herpesvirus, toxicity, self-trauma

Question 29

What is the definition of a scar?

Answer 29

Thin to thick fibrous tissue that replaces normal skin following injury or laceration to the dermis, hair regrowth may not occur

Question 30

What is the definition of atrophy?

Answer 30

Decrease in the size of a tissue due to a decreased number of cells

Question 31

What is dermal atrophy?

Answer 31

Thinning of dermal collagen fibres and decreased dermal thickness May be associated be alopecia

Question 32

What causes atrophy?

Answer 32

malnutrition and endocrinopathies

Question 33

What is the definition of urticaria?

Answer 33

* Smooth, Circumscribed, slightly elevated area of skin, caused by dermal oedema,

Question 34

What is angioderma?

Answer 34

Vascular reaction involving the deep dermis or subcut, consisting of oedema that manifests as giant wheals and are caused by dilation

Question 35

What is neoplasia?

Answer 35

abnormal mass of tissue, characterised by excessive and uncoordinated growth and persists in the same excessive manor after cessation of the stimuli which evoked a change

Question 36

What is albinism?

Answer 36

Inherited disorder that presents with an absence of melanin

Question 37

What is melanosis?

Answer 37

Excessive production of melanin in the skin usually secondary to skin damage