Descriptions of lesions

Description of Lesions

“He who studies skin diseases and fails to study the lesion first will never learn dermatology.”

Siemens(1891-1969)

Primary Lesions

Primary Lesions

Macule

-flat normal surface size <0.5cm in diameter

-area of color different from the surrounding skin or mucous membrane

Patch

-similar to a macule but size >0.5cm

Papule

-a solid, elevated lesion < 0.5 cm in diameter.

Plaque

-solid plateau-like elevation

-width >> height diameter > 0.5 cm

Nodule

-a solid, round or ellipsoidal, palpable lesion that has a diameter > 0.5 cm.

-depth of involvement and/or substantive palpability

Vesicle

-a fluid filled cavity sized <0.5cm in diameter

Bulla/blister

-a fluid filled cavity size >0.5cm

Pustule

-a vesicle or a papule filled with pus

Cyst

-an encapsulated cavity or sac lined with a true epithelium that contains fluid or semisolid material (cells and cell products such as keratin)

Lesions with size <0.5cm in ∅•Macule•Papule•vesicle•pustule

Summary to primary lesions

Secondary Lesions

Erosion

-loss of a portion or all of the viable epidermal or mucosal epithelium

-heals without scaring

Ulcer

-full thickness loss of epidermis & some dermis,

-heals with scaring

Atrophy

- depression of the surface due to thinning of the epidermis or dermis.

- there are often fine wrinkles & the blood vessels easily seen under the skin

Fissure

-linear split in the epidermis or dermis at an orifice (angle of the mouth or anus) over a joint or along a skin crease.

Surface features

- Scale : dry/flaky surface due to abnormal stratum corneum with accumulation of or increased shedding of keratinocytes

- Crust : serum, blood or pus that has dried/ accumulated on the surface – dry exudate

- Excoriations : are surface excavations of epidermis that result from scratching

- Lichenification : thickening of the epidermis with increased skin markings due to persistent scratching.

THE END