Skin lesions\ A skin lesion is a superficial growth or patch of the skin that does not resemble the area surrounding it.

Types of the Skin Lesions

Primary skin lesions\Primary skin lesions are variations in color or texture that may be present at birth, or that may be

acquired during a person's lifetime (Macule ,Papule ,Nodule,Vesicle,Bulla,Pustule,Wheal) Secondary skin lesions\

Secondary skin lesions are those changes in the skin that result from primary skin lesions, either as a natural

progression or as a result of a person manipulating (e.g. scratching or picking ) at a primary lesion. Secondary skin changes result from external factors such as scratching, trauma, infection, or changes caused by

healing.

(Scale,Crust,Fissure,Scar,Keloid,Erosion,Ulcer,Excoriation,Lichenification)

Macule\A macule is a change in the color of the skin. It is flat. A macule greater than 1 cm may be referred to as a patch.

Papule\A papule is a solid raised lesion that has distinct borders and is less than 1 cm in diameter. Papules may have a variety of shapes in profile (domed, flat-topped, umbilicated)

Plaque\is a plateau-like lesion > 10 mm or a group of confluent papules Nodule\A solid lesion that has distinct edges and that is usually more deeply rooted than a papule and more than 1cm in diameter

Vesicle\ is a circumscribed, elevated lesion containing serous fluid that is < 5 mm

Bulla\Circumscribed collection of free fluid > 0.5 cm Pustule\Vesicle containing pus (inflammatory cells)

Wheal\ Edematous, transitory plaque

Scale\Epidermal thickening

Crust\Dried serum Fissure\linear cleavage of skin which extends into the dermis Scars\permanent fibrotic changes that occur on the skin following damage to the dermis. Keloid\exaggerated connective tissue response of injured skin that extend beyond the edges of the original wound

Erosion\loss of epidermis (superficial) Ulcer\loss of epidermis and dermis

Excoriations\traumatized or abraded skin caused by scratching or rubbing Lichenification\ Rough, thick epidermis with exaggerated skin lines. This is often a characteristic of scratch

Configuration \The term "configuration" refers to the shape or morphology of lesions

Distribution\The term "distribution" refers to the clinical arrangement of skin lesions on the integument

((Localized ,Generalized,,Symmetric,Asymmetric,Discrete,Grouped,Confluent,

Examples:Macule\(Small pox,Purpura,Roseola)

Patch\(Measles,Flat moles,Freckles)

apule\(Actinic jeratosis,Senile sebaceous hyperplasia,Dermatofibroma)

Nodule\(Herpes simplex virus,Rheumatoid arthritis) 

Plaque\Psoriasis typically present with a plaque-like lesion

Vesicles\(Impetigo,Contact dermatitis,Insect bites)

Bulla( Bullous pemphigoid,Pemphigus,Dermatitis herpetiformis ,Chronic,bullous dermatosis ,Cutaneous radiation syndrome,Epidermolysis Bullosa)

Pustule\(Acne vulgaris,Rosacea,Folliculitis

Description of a skin lesion

When describing a skin lesion, it is important to note the following features:1. Size2. Type3. Shape and symmetry4. Colour and pigmentation5. Surface features (smooth; rough)6. Distribution over the body (extensor surfaces; flexor surfaces)

1) Types of skin lesions2) Colour-Examples of colour changes in lesions:Red/purpleErythema- redness due to increased blood flow to blood vessels (vasodilatation) in that area.

Purpura- red/purple discolouration due to extravasation of blood into the skin from a blood vessel.

BrownMelanin- a pigment found in the skin which gives a brown discolouration.Haemosiderin- the breakdown product of haemoglobin so can follow on from purpura and appears as a brown discolouration.

YellowLipid deposition- xanthelasma (cholesterol deposits around the eyelids) and xanthomata (cholesterol deposits in the tendons) can occur in hyperlipidaemia disorders.

Bilirubin- yellow discolouration due to jaundice (which is defined as bilirubin >35µmol)

3) Describe the surface features Normal- lesion lies below skin surfaceOr-There may be evidence at the skin surface such as-Break in epithelial surface- exudate, crust, ulcer or a fissure.Change in the size of epidermis/dermis-lichenificationor epidermal/dermal atrophy.Change in the stratum corneum (the outermost layer of the epithelium composed of dead cells)-Hyperkeratinosis- thickening of the stratum corneum due to increased keratin deposition in these cells.Scales

4) Define the area involving the lesion-Is the border well or poorly defined?Look at the centre of the lesion- is it continuous with the rest of the lesion or is it raised/depressed?

5) Desribe the shape of the lesion-The shape of the area on the skin surface- is it round, oval or irregular?Overall shape of the lesion- spherical, domed, pedunculated (lesion attached to skin by a narrow stalk), flat-topped.

6) Findings on palpation-Consistency-is it soft, firm, hard or indurated (can feel thickening within the lesion)?     or the lesion could have the consistency of normal skin. 

Example OSCE station: "Please describe the lesion on the right." In order to describe the lesion follow the 6 steps detailed above-1) Type-This is a primary lesion as it is a pathology in its own right rather than a consequence of an existing pathology, thus you can rule out secondary lesions such as scale, crust, ulcer etc.It is a non-raised lesion- thus you can rule out raised lesion types such as papule, nodule and plaqueThere is no fluid so you can rule out fluid-filled lesions such as pustule and abscess, vesicle and bullaThus the remaining two are macule and patch depending on the size of lesion, if it is >0.5cm it is a patch and <0.5cm it is a macule 2) Colour- the lesion is dark, a potential cause of this colour could be the pigment melannin3) Describe the surface features- this is a non-raised lesion which lies below the skin surface4) Define the area involving the lesion- the lesion has a poorly defined border5) Describe the shape of the lesion- the lesion has an irregular shape6) Findings on palpation- is it hard vs. soft? firm vs. moveable?Thus a summary of the description of this lesion could be something along the lines of:"This is a dark, non-raised macular lesion with a poorly defined border and an irregular shape. Given the dark discolouration and the nature of the shape and the lesion's border, a possible cause could be melanoma."