Macule

A flat colored lesion <2 cm in diameter, not raised above the surface of the surrounding skin 

Papule

A small, solid lesion <1 cm in diameter, raised above the surface of the surrounding skin

Patch 

A large (>2cm) flat lesion with a color different from the surrounding skin 

Nodule

A larger (1-5 cm) firm lesion raised above the surface of the surrounding skin.  Differs from a papule only in size

Plaque

A large (>1 cm) flat-topped, raised lesion.  Edges may be either distinct or gradually blend with surrounding skin.

Vesicle

A small, fluid filled lesion (eg. Poison Ivy blister)

Pustule

A vesicle filled with leukocytes (the presence of pustules does not necessarily signify the existence of an infection)

Bulla

A fluid-filled , raised, often translucent lesion >1 cm in diameter

Cyst

 A soft, raised, encapsulated lesion filled with semisolid or liquid contents

Wheal

A raised, erythematous papule or plaque, usually representing short-lived dermal edema

Telangiectasia

Dilated, superficial blood vessels

Lichenification

A distinctive thickening of the skin.

Excoriations

Linear, angular erosions that may be covered by crust and are caused by scratching 

Crust

Dried exudate of body fluids that may be either yellow or red 

Petechiae

A small red or purple spot on the body, caused by a minor hemorrhage.