Macule
Circumscribed flat lesion less than 5 mm and usually discolored often red
A mat is flat so it makes sense
Patch
Circumscribed flat lesion more than 5 mm and usually discolored often red
A patch is flat so it makes sense
Papule
Elevated dome shaped or flat topped lesion less than 5 mm
Nodule
Elevated spherical lesion more than 5 mm
Plaque
Elevated flat topped lesion usually more than 5 mm often formed by merging papules
Vesicle
Fluid filled raised lesion less than 5 mm
Bulla
Fluid filled raised lesion more than 5 mm
Blister
General term for vesicle or bulla
Pustule
Discrete pus filled raised lesion
Wheal
Itchy transient elevated lesion with variable blanching and erythema due to dermal edema
Scale
Dry horny plate like excrescence usually due to imperfect keratinization
Lichenification
Thickened rough skin with prominent markings usually from repeated rubbing
Excoriation
Traumatic lesion with epidermal breakage causing a raw linear area deep scratch
Onycholysis
Separation of nail plate from nail bed
Hydropic swelling (ballooning)
Intracellular edema of keratinocytes
Exocytosis
Infiltration of the epidermis by inflammatory or circulating blood cells
Erosion
Discontinuity of the skin with incomplete loss of the epidermis
Ulceration
Discontinuity of the skin with complete loss of the epidermis often extending into dermis or subcutaneous fat
