Physical Reference

Lesion Types

Primary (Basic) Lesions
Click name or picture for detailed information and images

macule
circumscribed flat discoloration

papule
elevated solid lesion (up to 5mm)

nodule
palpable solid (round) lesion, deeper than a papule

plaque
circumscribed, superficially elevated solid lesion (greater than 5 mm) (often, a confluence of papules)

wheal (hive)
pale-red edematous plaque - round or flat-topped and transient

pustule
elevated collection of purulence

vesicle
circumscribed elevated collection of fluid (up to 5 mm in diameter)

bulla
circumscribed elevated collection of fluid (greater than 5 mm in diameter)
Secondary (Sequential) Lesions
Click name or picture for detailed information and images

scale (desquamation)
excess dead epidermal cells

crust
a collection of dried serum, blood, or purulence

erosion
superficial loss of epidermis

ulcer
focal loss of epidermis and dermis

fissure
linear loss of epidermis and dermis

atrophy
depression in the skin from thinning of epidermis and/or dermis

excoriation
erosion caused by scratching

lichenification
thickened epidermis with prominent skin lines (induced by scratching)