Dermatology - Clinical skills

Question 1

What are the 4 aspects of skin examination?

Answer 1

Inspect
Describe
Palpate
Systemic check

Question 2

What are the key features of inspecting a skin lesion?

Answer 2

This should involve a general observation, noting the site and number of lesions. If lesions are multiple then note the pattern of their distribution and configuration.

Terms that can be used to describe distribution include generalised, widespread, localised, flexural, extensor, pressure areas, photosensitive or Koebner phenomenon.

Terms that are used to describe configuration are discrete, confluent, linear, target, annular and discoid.

Question 3

What does a generalised lesion mean?

Answer 3

A lesion all over the body

Question 4

What is a widespread lesion?

Answer 4

Extensive (covering a sizeable portion, but not all, of the body)

Question 5

What is a localised lesion?

Answer 5

Restricted to one area of skin only

Question 6

What is a flexural rash/ lesion?

Answer 6

Located on the body folds i.e. groin, neck, behind the ears, popliteal and anticubital fossa. This is opposed to extensor rashes which are found on the knees, elbows and shins.

Question 7

What are the pressure areas?

Answer 7

Sacrum, buttocks, ankles and heels.

Question 8

What is a photosensitive rash?

Answer 8

A rash affecting sun exposed areas such as the face, neck and back of hands.

Question 9

What is the Koebner phenomenon?

Answer 9

A linear eruption arising at the site of trauma.

Question 10

What is a discoid lesion?

Answer 10

Individual lesions separated from one another.

Question 11

What is a confluent lesion?

Answer 11

Lesions merging together

Question 12

What is a target lesion?

Answer 12

Concentric rings (like a dartboard) - seen in erythema multiforme.

Question 13

What is an annular lesion?

Answer 13

A lesion that resembles a ring or circle - e.g. tinea corporis (ring worm)

Question 14

What is a discoid lesion?

Answer 14

Coin shaped/ round lesion - e.g. discoid eczema

Question 15

How should one describe a lesion?

Answer 15

SCAM:

• Size (widest diameter), Shape
• Colour
• Associated secondary change
• Morphology, Margin (border)

If the lesion is pigmented remember ABCD (the presence of any of these features increases the likelihood of malignancy)

• Asymmetry (lack of mirror image in any of the four quadrants)
• Irregular Border
• Two or more Colours within the lesion
• Diameter >6cm

Question 16

What does erythema mean?

Answer 16

Redness (due to inflammation and vasodilatation) which blanches on pressure - e.g. palmar erythema

Question 17

What is purpura?

Answer 17

Red or purple colour (due to bleeding into the skin or mucous membrane) which does not blanch on pressure - petechiae (small pinpoint macules) and ecchymoses (larger bruise like patches)

• purpuric rash due to low platelets (i.e. thrombocytopaenia) is not palpable
• purpuric rash due to vasculitis is palpable (due to vessel inflammation)

Question 18

What is hypopigmentation?

Answer 18

Areas of paler skin - e.g. pityriasis versicolor (a superficial fungus infection)

Question 19

What is depigmentation?

Answer 19

White skin due to absence of pigmentation - e.g. vitiligo (loss of skin melanocytes)

Question 20

What is hyperpigmentation?

Answer 20

Darker skin which may be due to various causes (e.g. post inflammatory) - e.g. Melasma (increased melanin pigmentation)

Question 21

What is a macule?

Answer 21

This is a descriptive term relating to the primary lesion. It means a flattened area of altered colour - e.g. freckles.

Question 22

What is a patch?

Answer 22

A larger flattened area of altered colour - e.g. vascular malformation (naevus flammeus/ port wine stain)

Question 23

What is a papule?

Answer 23

A solid raised lesion <0.5cm in diameter - e.g. xanthomata

Question 24

What is a nodule?

Answer 24

A solid raised lesion >0.5cm in diameter with a deeper component - e.g. pyogenic granuloma

Question 25

What is a plaque?

Answer 25

Type of primary skin lesion

A palpable scaling raised lesion >0.5cm in diameter - e.g psoriasis

Question 26

Vesicle

Answer 26

Raised, clear fluid filled lesion <0.5cm in diameter

Question 27

Bulla

Answer 27

Raised, clear fluid filled lesion >0.5cm in diameter - e.g. reaction to insect bites

Question 28

Pustule

Answer 28

Term to describe a primary lesion. Pus containing lesion <0.5cm in diameter - e.g. acne

Question 29

Abscess

Answer 29

Localised accumulation of pus in the dermis or subcutaneous tissue

Question 30

Wheal

Answer 30

Transient raised lesion due to dermal oedema - e.g. urticaria

Question 31

Boil/ faruncle

Answer 31

Staphylococcal infection around or within a hair follicle

Question 32

Carbuncle

Answer 32

Staphylococcal infection of adjacent hair follicle

Question 33

What are secondary lesions?

Answer 33

Lesions that involve from the primary lesion

Question 34

Excoriation

Answer 34

Loss of epidermis following trauma - e.g. itching in eczema

Question 35

Lichenification

Answer 35

Well defined roughening of the skin with accentuation of skin margins - e.g. lichenification due to chronic rubbing in eczema

Question 36

Scales

Answer 36

Flakes of stratum corneum

Question 37

What are crusts?

Answer 37

Rough surface consisting of dried serum, blood, bacteria and cellular debris that has exuded through an eroded epidermis (e.g. from a burst blister) - e.g. impetigo

Question 38

What is a scar?

Answer 38

New fibrous tissue which occurs post wound healing, and may be atrophic (thinning), hypertrophic (hyperproliferation within wound boundary) or keloidal (hyperproliferation beyond wound boundary).

Question 39

What is an ulcer?

Answer 39

Loss of epidermis and dermis

Question 40

What is a fissure?

Answer 40

An epidermal crack often due to excess dryness

Question 41

What are striae?

Answer 41

Linear areas which progress from purple to pink to white, with the histopathological appearance of a scar (associated with excess steroid use and glucocorticoid production, growth spurts and pregnancy)