Excoriation

Traumatic lesion breaking the epidermis and causing a raw linear area (i.e., deep scratch); often self-induced

Lichenification

Thickened, rough skin (similar to a lichen on a rock); usually the result of repeated rubbing

Macule, Patch

Circumscribed, flat lesion distinguished from surrounding skin by color. Macules are 5 mm in diameter or less, patches are greater than 5 mm.

Onycholysis

Separation of nail plate from nail bed

Papule, Nodule

Elevated dome-shaped or flat-topped lesion. Papules are 5 mm or less across, while nodules are greater than 5 mm in size.

Plaque

Elevated flat-topped lesion, usually greater than 5 mm across (may be caused by coalescent papules)

Pustule

Discrete, pus-filled, raised lesion

Scale

Dry, horny, platelike excrescence; usually the result of imperfect cornification

Vesicle, Bulla, Blister

Fluid-filled raised lesion 5 mm or less across (vesicle) or greater than 5 mm across (bulla). Blister is the common term for either.

Wheal

Itchy, transient, elevated lesion with variable blanching and erythema formed as the result of dermal edema