MORPHOLOGY Primary Lesions Secondary Lesions Special Lesions

Primary Lesions

Macule Flat discoloration (any color) up to 1 cm

Patch Flat discoloration (any color) greater than 1 cm

Papule Palpable lesion up to 1 cm May become confluent to form plaque

Plaque Palpable lesion greater than 1 cm

Nodule Circumscribed, elevated, solid lesion greater than 1 cm

Tumor A very large nodule

Vesicle Circumscribed collection of free fluid up to 1 cm

Pustule Circumscribed collection of pus up to 1 cm

Bullae Circumscribed collection of free fluid greater than 1 cm

Wheal (hive) Firm, edematous plaque resulting from infiltration of the dermis with fluids Transient; may last only a few hours

Secondary Lesions

Scales Excess dead epidermal cells that are produced by an abnormal keratinization and shedding

Crust Collection of dried serum and cellular debris (a scab)

Erosion Focal loss of epidermis Does not pass the dermoepidermal junction Heals without scarring

Ulcer Focal loss of epidermis and dermis Heals with scarring

Fissure Linear loss of epidermis and dermis with sharply defined nearly vertical walls

Atrophy Depression in the skin resulting from thinning of the epidermis or dermis

Scar Abnormal formation of connective tissue implying dermal damage; After injury or surgery scars are initially thick and pink but with time become white and atrophic

Special skin lesions

Comedone Plug of sebaceous and keratinous material lodged in the opening of a hail follicle Closed comedone = white head Open comedone = black head

Excoriation An erosion caused by scratching; often linear

Lichenification Area of thickened epidermis induced by scratching Skin lines are accentuated so that the surface looks like tree-barking

Petechiae Circumscribed tiny deposit of blood (up to 0.5 cm)

Purpura Circumscribed deposit of blood greater than 0.5 cm

Ecchymoses Very large purpuric lesions

Name that lesion! Use the proper terminology to describe the predominant lesion (primary, secondary or special) shown in the following photos.

Macules

Papules

Pustules

Nodule

Patch

Tumor

Vesicles

Scales

Crust

Patches

Erosion

Fissures

Atrophy

Lichenification

Comedones

Erosion & Crust

Bullae

Papules

Fissures

Plaques

Lichenification