Skin Terminology Rich Callahan PA-C, ICM I Summer 2009

It’s all about the descriptive terminology! Dermatology unique in that PE almost entirely visual, and you need to accurately and quickly describe what you see.

Description of skin lesions always has the same basic parameters Type of skin lesion (papule, macule, etc) Color Margination Consistency Shape Arrangement Distribution (where anatomy comes in!)

Descriptive Terminology: Types of Skin Lesions Papule – a solid, raised lesion 5mm or less in diameter Macule – a defined, flat area whose color is distinctly different from surrounding skin (larger version of macule is patch) 1 cm or less in diameter Plaque – a raised, superficial, solid lesion 5mm or more in diameter (when papules become confluent with one another they become plaques) Nodule – well-defined, deeply seated lesion >5mm diameter. A large nodule is called a tumor.

Descriptive Terminology Pustule – flat to slightly raised, defined pocket of leukocytes/serous fluid, any size Vesicle – a blister up to 5mm diameter Bulla – blister greater than 5mm diameter. Plural is bullae Wheal – firm, edematous papules and plaques. Usually transitory (hives.) No appreciable surface textural changes (epidermis unaffected.)

Descriptive Terminology Scale – dead epidermis – “white flakes” Crust – Dried serum, blood, etc. “Scab” Erosion – An area of skin where the outer layer (epidermis) has been eroded away. By definition, superficial to dermoepidermal junction, will not cause a scar. Ulceration – Similar to erosion, but defect penetrates into dermis. Fissure – Sharply defined crack in the skin which penetrates down to dermis

Color Any color you see as appropriately descriptive, using language that another person reading your notes would understand. Red, blue, green, black, light/dark brown, orange, magenta, cayenne pepper, etc. Is there mixing of colors, and if so is it symmetrical-appearing? Example: When pressed with a glass slide, skin lesions of sarcoidosis often blanch and take on an “apple jelly” color

A few physical exam findings need to be described more specifically however! Erythema (from Greek “to redden”) – That unique redness seen in human skin resulting from enlargement (congestion) of blood vessels. Usually blanches with manual pressure. Classic example is sunburn seen in fair-skinned people. Individual blood vessels often visible with magnification.

A few physical exam findings need to be described more specifically however! Purpuric, or violaceous – has the purplish color of a bruise, and does not blanch when pressed with glass slide. Due to direct extravasation(blood left vessels into tissues) of blood into dermis. Important to recognize/describe this type of lesion as is presenting sign of many important diseases and injuries.

Margination Sharply marginated; well-defined Poorly defined; hazy borders – can seem like gradual transition from lesion to normal skin. Borders can be linear, arcuate, geographic Borders can be regular: Composed of smooth, generally straight lines. Borders can be irregular: Composed of varying, squiggly, generally crooked lines.

Consistency Firm, soft, hard, gelatinous, etc. Rubbery, tissue paper, boggy, warty, stuck- on appearing, moist, gritty, cracked china, crazy pavement, fish scale, greasy, etc….. Hot/cold/warm Freely mobile vs. fixed Tenderness to palpation

Shape Round, trapezoidal, polygonal, ovular, annular, polycyclic, serpiginous, linear, etc. Can get more descriptive: star-shaped, pac-man, ink spot, umbilicated, etc. Example: Nummular eczema, comes for the Latin word for “coin” because characteristic lesions are homogenous and round, usually somewhere between the size of a nickel or quarter.

Arrangement (I.e., the way in which lesions are distributed on the patient.) Scattered, or disseminated; widespread. Can be many or few. Alternatively, can be localized; discrete. Groups of lesions can be arranged in annular, linear, arciform, reticulated, serpiginous or herpetiform shapes. “Buckshot” – lesions appear scattered in a way reminiscent of the scattering of shot from a shotgun barrel Is there symmetry in arrangement of lesions between body areas, or does it appear random?

Distribution Where on the body do the lesions present, and to what extent? – isolated, localized, regional, widespread. Describing a specific area comes down to surface anatomy. Anatomic patterns: Intertriginous, follicular, dependent areas, dermatomal, etc. Flexor/extensor extremities Is it limited to sites of sun-exposure, windburn,pressure, contact with clothing, furniture, etc?

Putting it all together Let’s check out some skin lesions and talk about how to describe them!