Skin

Macule

A flat, non-poppable skin color change less than one centimeter with circumcised borders.

Patch

A flat, non-poppable skin color change greater than one centimeter that may have irregular borders.

Papule

An elevated palpable solid mass less than 0.5 centimeters with circumscribed borders.

Plaque

An elevated palpable solid mass greater than 0.5 centimeters that may be coalist with flat tops.

Nodule

An elevated palpable solid mass between 0.5 and 2 centimeters with circumscribed borders.

Tumor

An elevated palpable solid mass greater than 2 centimeters that may not have sharp borders.

Vesicle

An elevated palpable mass containing serous fluid, less than 0.5 centimeters.

Bola

An elevated palpable mass containing serous fluid, greater than 0.5 centimeters.

Wheal

An elevated mass with transient borders, caused by movement of serous fluid into the dermis.

Pustule

A pus-filled vesicle or bola.

Cyst

An encapsulated fluid-filled or semi-solid mass in the subcutaneous tissue or dermis.

Erosion

Loss of superficial epidermis that does not extend to the dermis, resulting in a depressed, moist area.

Ulcer

Skin loss extending past the epidermis, possibly involving necrotic tissue loss and bleeding.

Fissure

A linear crack in the skin that may extend to the dermis.

Scale

Flakes secondary to desquamated, dead epithelium that may adhere to the skin surface.

Crust

Dried residue of serum, blood, or pus on the skin surface.

Scar

A skin mark left after healing of a wound or lesion, representing replacement by connective tissue.

Keloid

A hypertrophied scar tissue secondary to excessive collagen formation during healing.

Atrophy

Thin, dry, transparent appearance of epidermis with loss of surface marking due to collagen and elastic loss.

Lichenification

Thickening and roughening of the skin with accentuated markings due to repeated rubbing or irritation.

Bow lines

Transverse depressions in the nails reflecting delayed growth due to severe illness or local trauma.

Paronychia

An inflammation of the skin around the nail, usually accompanied by tenderness and redness.

Pitted surface of nails

A definite indication of psoriasis.