Introduction to skin disease

Question 1

Primary Lesions

Answer 1

• Nodule
• Papule
• Macule
• Patch
• Vesicle
• Bulla
• Pustule
• Plaque
• Erythema

Question 2

Secondary Lesions

Answer 2

• Scale
• Excoriation
• Lichenification
• Crust
• Atrophy

Question 3

Nodule

Answer 3

• solid raised lesion >3mm in diameter, contains no fluid

Question 4

Papule

Answer 4

• small solid raised lesion e.g closed comedone

Question 5

Macule

Answer 5

• a flat coloured lesion, not raised e.g freckle

Question 6

Patch

Answer 6

• large flat coloured lesion. Differs from macule in size

Question 7

Vesicle

Answer 7

• small, fluid filled lesion <1cm e.g vesicles in allergic contact dermatitis

Question 8

Bulla

Answer 8

• fluid filled, raised > 1cm

Question 9

Cyst

Answer 9

• soft, raised, encapsulated lesion filled with semi-solid or liquid contents. Deeper and more significant than a pustule

Question 10

Pustule

Answer 10

• vesicle filled with fluid and leucocytes

Question 11

Plaque

Answer 11

• large, flat-topped, raised lesion. Edges can be distinct as in psoriasis or blend as in eczematous dermatitis

Question 12

Erythema

Answer 12

• redness of skin due to capillary dilatation

Question 13

Scale

Answer 13

• collection of cells which have separated from the epidermis

Question 14

Excoriation

Answer 14

• injury caused by scratching when the epidermis or dermis are removed

Question 15

Lichenification

Answer 15

• distinctive thickening of skin characterised by accentuated skin-fold markings

Question 16

Crust

Answer 16

• dried exudate of body fluids that may be yellow (serous exudate) or red (haemorrhagic exudate

Question 17

Atrophy

Answer 17

• an acquired loss of substance e.g. dermal or epidermal

Question 18

Examining skin lesions

Answer 18

Inspection of the lesion(s) should consider the following:
Distribution
Extensor: extensor surfaces including elbows and knees, e.g. psoriasis
Flexural: Affecting skin folds, e.g. atopic eczema
Follicular: Affecting areas with increased numbers of sebaceous glands, e.g. acne
Type, shape, colour and size of primary lesion (and presence of any secondary lesion)
Configuration of the lesion, e.g.
Discrete: individual lesions, clearly separated from one another, e.g. mole
Linear: lesions in the shape of a line (e.g. excoriations)
Annular: ring-like lesions, e.g. tinea corporis
Generalised: may suggest systemic aetiology
If a pigmented lesion, need to consider screening for signs suggestive of malignant melanoma, e.g. using the ABCDE criteria
Palpation: e.g. for temperature, tenderness (consider infection control)

Question 19

Skin lesion history taking

Answer 19

Evolution of symptoms
How and when developed (how long ago)
Changed over time?
Associated symptoms
Itch, malaise, systemic symptoms, pain, etc.
Current or recent medications
Especially recent changes suggesting drug-induced cause
Ongoing or previous illness (medical hx.)
Some may have skin manifestations
History of allergies
Food, drug, chemicals, occupation, etc.
Exacerbating or relieving factors
treatment, weather changes, etc.
Presence of photosensitivity
Family history, e.g. skin disease, atopy, etc.