Examination

Question 1

How would describe a skin lesion?

Answer 1

Use SCAM

S= size
C= colour 
A= associated secondary change
M= morphology, margin (border)

If the lesion is pigmented use ABCD (any of these features increase the likelihood of a melanoma)

A= asymmetry 
B= irregular Border 
C= two or more Colours within the lesion
D= Diameter >6mm

Question 2

What is the general structure of a dermatology examination?

Answer 2

Look and describe the lesion

Palpate individual lesions for: surface, consistency, mobility, tenderness and temperature

Systemic check: examine the nails, scalp, hair, mucous membranes

General examination of all systems

Question 3

What is a comedone?

Answer 3

A plug in a sebaceous follicle, contains altered sebum, bacteria and cellular debris
Can either present as open or closed

Question 4

What do the following mean…

1- generalised
2- widespread 
3- localised
4- flexural
5- extensor 
6- Pressure areas 
7- dermatome 
8- photosensitive 
9- koebner phenomenon

Answer 4

1- all over the body
2- extensive
3- one area of skin only
4- body folds- groin, neck, behind ears, popliteal, antecubital fossa
5- knees, elbows, shins
6- heels, ankles, sacrum, buttocks
7- an area of skin supplied by a single spinal nerve
8- sun exposed area (face, neck, back of hands)
9- linear eruption arising at the site of trauma

Question 5

What do the following configurations (pattern or shape of grouped lesions) mean..

A) discrete
B) confluent 
C) linear 
D) target 
E) annular 
F) discoid/ nummular

Answer 5

A) individual lesions which are separated from each other
B) lesions merging together
C) in a line
D) concentric rings (like a dartboard)
E) like a circle or ring (tinea corporis- ringworm)
F) coin shaped

Question 6

How can you describe the colour of a lesion…

Answer 6

Erythema (due to inflammation and vasodilatation) blanches on pressure
Ie: palmar erythema

Purpura (red or purple colour which is due to bleeding into the skin or mucous membrane) Doesn’t blanch on pressure
Purpura can either be petechiae (small pinpoint maccules) or ecchymoses (larger bruise like patches)

Hypopigmentation (areas of paler skin)

Depigmentation (white skin due to absence of melanin)

Hyperpigmentation (increased melanin pigmentation)

Question 7

Give an example of the following…

erythema

Purpura

Hypopigmentation

Depigmentation

Hyperpigmentation

Answer 7

A) palmar erythema- seen in cirrhosis
B) henoch schonlein purpura (palpable small vessel vasculitis)
C) pityriasis versicolor (superficial fungal infection)
D) vitiligo
E) melasma

Question 8

How do you describe the morphology of a lesion?

Answer 8

Macule= flat area of altered colour ie: freckles

Patch= larger flat area of altered colour or texture ie: naevus flammeus/ port wine stain)

Papule= a solid raised lesion <0.5cm in diameter

Nodule= a solid raided lesion >0.5cm in diameter

Plaque= palpable scaling raised lesion >0.5cm in diameter

Vesicle (small blister)= raised clear fluid filled lesion < 0.5cm in diameter

Bulla= raised clear fluid filled lesion >0.5cm in diameter

Pustule= pus containing lesion which is <0.5cm in diameter

Abscess= localised accumulation of pus in the dermis or subcut tissues

Wheal= transient raised lesion due to dermal oedema

Boil/furuncle= staphylococcal infection around or within a hair follicle

Carbuncle= staph infection of adjacent hair follicles (multiple boils/furuncles)

Question 9

What is meant by secondary lesions?

Answer 9

Lesions which evolve from the primary lesions 
Examples...
- excoriation 
- lichenification 
- scales 
- crust 
- scar
- ulcer 
- fissure (epidermal crack often due to excess dryness) 
- striae

Question 10

What is meant by…
A) alopecia
B) hirsutism
C) hypertrichosis

Answer 10

A) loss of hair
B) androgen dependent hair growth in a female
C) non androgen dependent pattern of excessive hair growth ie: pigmented naevi

Question 11

What is clubbing and what is it caused by?

Answer 11

Loss of angle between the posterior nail fold and nail plate

Caused by…

• suppurative lung disease
• cyanotic heart disease
• IBD
• idiopathi

Question 12

What is koilonychia and what is it associated with?

Answer 12

Spoon shaped depression of the nail plate

Iron deficiency anaemia, congenital, idiopathic

Question 13

What is onycholysis? What is it caused by?

Answer 13

Seperation of the distal end of the nail plate from the nail bed
Fungal nail infection, trauma, psoriasis, hyperthyroidism

Question 14

What is pitting?

Answer 14

Punctate depressions of the nail plate

Associations- psoriasis, eczema, alopecia areata

Question 15

What are the functions of normal skin?

Answer 15

Protective barrier against environmental insults 
Temperature regulation 
Sensation 
Vit D synthesis 
Immunosurveillance 
Appearance/cosmesis

Question 16

What are skin appendages?

Answer 16

Structures formed from skin derived cells- hair, nails, sebaceous glands, sweat glands.

Question 17

There are four main cell types of the epidermis, what are they and what are their function?

Answer 17

Keratinocytes, langerhans cells, melanocytes and merkel cells

Keratinocytes- produce keratin as a protective barrier

Langerhans cells- present antigens and activate T lymphocytes for immune protection

Melanocytes- produce melanin, this gives pigment to the skin and protects the cell nuclei from UV radiation induced DNA damage

Merkel cells- contain specialised nerve endings for sensation

Question 18

What are layers of the epidermis?

Answer 18

Deepest to most superficial….

• stratum basale (basal cell layer- actively dividing cells, deepest layer
• stratum spinosum (prickle cell layer)
• stratum granulosum
• stratum corneum (layer of keratin, most superficial layer)

Question 19

What may pathology of the epidermis involve?

Answer 19

A) changes in epidermal turnover time (psoriasis- reduced epidermal turnover time)

B) changes in the surface of skin or loss of epidermis- scales, crusting, exudate, ulcer

C) changes in pigmentation

Question 20

What is the average epidermal turnover time?

Answer 20

Turnover= migration of cells from the basal cell layer to the horny layer

It is about 30 days

Question 21

What is the dermis made up of?

Answer 21

Collagen
Glycosaminoglycans
Elastin

Collectively they provide the dermis with strength and elasticity

The dermis also contains immune cells, nerves, skin appendages as well as lymphatic and blood vessels.

Question 22

What might the pathology of the dermis involve?

Answer 22

Changes in the contour of the skin/loss of dermis
Disorders of skin appendages- hair/acne (sebaceous glands)
Changes related to lymphatic and blood vessels

Question 23

What is the role of sebaceous glands?

Answer 23

Sebaceous glands produce sebum via. hair follicles (collectively called a pilosebaceous unit), when they secrete sebum onto the skin surface it lubricates and waterproofs the skin

Question 24

How are sebaceous glands stimulated?

Answer 24

They are stimulated by the conversion of androgens to dihydrotestosterone and therefore become active at puberty

Question 25

What does pathology of sebaceous gland involve?

Answer 25

Increased sebum production and therefore bacterial colonisation- acne

Sebaceous gland hyperplasia

Question 26

What is the role of sweat glands and what are they innervated by?

Answer 26

Sweat glands regulate body temperature

They are innervated by the sympathetic nervous system

Question 27

What are the two types of sweat glands?

Answer 27

Eccrine and apocrine
Eccrine- widely distributed in the skin
Apocrine- found in the axilla, areolae, genitals and anus and modified glands are found in the external auditory canal

Question 28

what are the stages of wound healing?

Answer 28

Haemostasis (vasoconstriction and platelet aggregation, clot formation)

Inflammation- vasodilatation, migration of neutrophils and macrophages
Phagocytosis of cellular debris and invading bacteria

Proliferation- granulation tissue formation and angiogenesis
Re- epithelialisation

Remodelling- collagen fibre re-organisation, scar maturation