Language of Skin - Dermatology Overview

Flashcards covering dermatology vocabulary, primary and secondary skin lesions, clinical signs, and diagnostic procedures.

Primary Lesion

A skin lesion directly associated with the disease process and described using established dermatological terminology.

Secondary Lesion

A modification of a primary lesion that results from traumatic injury, evolution from the primary lesion, or other external factors.

Macule

A circumscribed area of change in skin color without elevation or depression that is not palpable.

Macular Exanthem

A rash consisting of macules.

Papule

A superficial, elevated, palpable solid lesion generally considered $<0.5\,cm$ in diameter.

Diascopy

A clinical test used to determine whether a macular lesion is blanching or non-blanching.

Plaque

A plateau-like elevation above the skin surface that occupies a relatively large surface area in comparison with its height.

Lichenification

A less well-defined large plaque where the skin appears thickened and skin markings are accentuated.

Patch

A lesion fitting between a macule and a plaque, characterized as a barely elevated plaque.

Nodule

A palpable, solid, round, or ellipsoidal lesion larger than a papule that may involve the epidermis, dermis, or subcutaneous tissue.

Wheal

A rounded or flat-topped, pale red papule or plaque due to dermal papillary edema that characteristically disappears within $24$ to $48\,h$.

Urticaria

A rash consisting of wheals, also referred to as an urticarial exanthema.

Vesicle

A circumscribed, elevated, superficial cavity containing fluid that measures $<0.5\,cm$ in size.

Bulla

A circumscribed, elevated, superficial cavity containing fluid that measures $>0.5\,cm$ in size.

Pustule

A circumscribed superficial cavity of the skin containing purulent exudate.

Cyst

A cavity containing liquid, solid, or semisolid materials that feels resilient upon palpation.

Crust

A lesion formed when serum, blood, or purulent exudate dries on the skin surface.

Ecthyma

A ulcerative condition occurring when exudate involves the entire epidermis forming thick, adherent crusts accompanied by necrosis of deeper tissues.

Scales

Flakes of stratum corneum, also known as squames.

Papulosquamous Exanthem

A rash consisting of papules with scales.

Erosion

A skin defect involving only the epidermis that heals without scar formation.

Ulcer

A skin defect extending into the dermis or deeper into the subcutis that always heals with scar formation.

Scar

The fibrous tissue replacement of a tissue defect caused by a previous ulcer or wound.

Atrophy

A diminution of some or all layers of the skin.

Epidermal Atrophy

Thinning of the epidermis that becomes transparent, revealing papillary and subpapillary vessels with loss of skin texture and cigarette paper-like wrinkling.

Dermal Atrophy

Loss of connective tissue of the dermis resulting in depression of the lesion.

Wickham Striae

Fine morphologic details observed in lichen planus under hand lens magnification.

Wood Lamp

An ultraviolet long-wave light ($365\,nm$) used to visualize fluorescent pigments and subtle color differences of melanin pigmentation.

Dermoscopy

A noninvasive technique using a hand lens with built-in lighting and magnification of $10\times$ to $30\times$ to inspect deeper layers of the epidermis.

Darier Sign

A positive sign when a brown macular or slightly papular lesion of urticaria pigmentosa becomes a palpable wheal after being rubbed.

Auspitz Sign

A positive sign when slight scratching or curetting of a scaly lesion reveals punctate bleeding points within the lesion.

Nikolsky Phenomenon

A positive sign when the epidermis is dislodged from the dermis by lateral, shearing pressure with a finger, resulting in an erosion.

Patch Testing

A diagnostic test used to document and validate allergic contact sensitization using shallow cups (Finn chambers) applied for $24$ to $48\,h$.

Photopatch Testing

A combination of patch testing and UV irradiation of the test site used to document photoallergy.

Prick Testing

A diagnostic test for type I allergies where a drop of allergen solution is pierced into the skin, yielding a wheal reaction within $20\,min$.

Tzanck Preparation

A diagnostic preparation that reveals acantholytic cells in acantholytic diseases or multinucleated giant cells in herpes simplex, herpes zoster, and varicella.