Copy of `UCSF - Dermatology Glossary`

The wordlist doesn't exist anymore, or, the website doesn't exist anymore. On this page you can find a copy of the original information. The information may have been taken offline because it is outdated.

UCSF - Dermatology Glossary Category: Health and Medicine > Skin health and disease Date & country: 23/03/2011, UK Words: 158

Onychomycosis
Chronic fungal infection of the nails causing chronically thickened, splitting, rough, discolored nails. Also known as tinea unguium.

Papule
A well-circumscribed, elevated, solid lesion, less than 1 cm. Usually dome shaped.

Papulosquamous
Papulo refers to papules and plaques and squamous means scaly. This is a term used to describe an eruption of skin lesions composed of these two components

Parakeratosis
A microscopic term referring to the retention of nuclei in the keratinocytes of the the keratinizing layer of epidermis (stratum corneum).

Paronychia
Supperative, or pus-forming, inflammation of the nail fold, or the soft tissues at the proximal and lateral margins of the nail. This commonly results in separation of the skin from the proximal nail.

Patch
A circumscribed area of discoloration, greater than 1 cm, which is neither elevated or depressed relative to the surrounding skin.

Pediculosis
The state of being infested with lice. The typical skin findings include excoriated papules and pustules on the trunk and the perineum.

Pemphigus Vulgaris
Autoantibodies to epidermal components leading to superficial, suprabasal, and flaccid bullae. Slow to heal and high mortality without treatment.

Perioral Dermatitis
An acne-like eruption of small erythematous papules and pustules that cluster around the mouth. Often triggered by higher potency topical steroids.

Petechiae
Small, nonblanching, erythematous macules, less than 0.5 cm (pinpoint to pinhead size), due to rupture of small blood vessels leading to hemorrhage.

Photodistribution
Areas of the skin that receive the most exposure to the sun and are commonly involved in photosensitivity eruptions. Areas: face, dorsal hands and forearms, posterior and lateral neck.

Pilar Cyst
A benign cyst commonly found in the scalp, appearing as a flesh-colored, firm but malleable nodule or tumor.

Pityriasis Alba
An idiopathic hypopigmentary condition appearing as white patches with indistinct margins covered with a fine scale.

Pityriasis Rosea
A self-limited, generalized eruption of erythematous oval macules and papules. These lesions occur along skin cleavage lines of the trunk and extremities and the distribution is often likened to the branches of a Christmas tree.

Plaque
A well-circumscribed, elevated, superficial, solid lesion, greater than 1 cm in diameter. Usually

Port-Wine Stain
A type of congenital capillary malformation that presents as a large irregular macule or patch, often red or violaceous in color.

Potassium Hydroxide Preparation
An in-office diagnostic test that uses potassium hydroxide (KOH) to diagnose a fungal infection of the skin.

Primary Lesion
A primary lesion is a skin lesion directly associated with the disease process and is described with established dermatological terminology (e.g. macule, papule, patch...).

Pruritus
Commonly known as itching, this is a sensation that produces the desire to scratch.

Psoriasis
A chronic condition characterized by an eruption of sharply demarcated, erythematous papules and plaques with overlying silvery scale. Although the lesions can occur anywhere on the skin, the classic distribution is on the scalp, elbows, and knees.

Purpura
Nonblanching violaceous (purple) discoloration of the skin due to blood that has extravasated outside of vessel walls. May be palpable or non-palpable.

Pustule
A small (< 1 cm in diameter), circumscribed superficial elevation of the skin that is filled with purulent material.

Pyogenic Granuloma
An acquired, erythematous round papule or nodule that projects from the skin or mucosa. These lesions are made of friable granulation tissue and bleed easily.

Reticular
Net-like shape or arrangement.

Rhinophyma
Dermal and sebaceous gland hyperplasia of the nose seen with chronic acne rosacea of several years. Fibrosis, increased vascularity, and dilated veins and hair follicles may also be seen. Noses are often described as bulbous in shape and may be reddish.

Scabies
An infestation of the epidermis with the human mite. The typical skin findings include pruritic, excoriated papules on the hands, elbows, axillae, abdomen, genitalia, and feet. A diagnostic finding is the burrow

Scaling
Visible fragments of the stratum corneum as it is shed from the skin.

Sebaceous Gland Hyperplasia
Proliferation of sebaceous glands around a hair follicle. Lesions appear as small (1-3 mm), superficial, yellowish papules with a central pore.

Seborrheic Dermatitis
A chronic inflammatory process commonly affecting the face, eyebrows, scalp (dandruff), chest, and perineum. The typical skin findings range from fine white scale to erythematous patches and plaques with greasy, yellowish scale.

Seborrheic Keratosis
A superficial benign neoplasm of epidermal cells that presents as a papule or plaque with a characteristic

Secondary Lesion
Modification of a primary lesion, such as scale, crust, erosion, ulceration, scar, or fissuring, that results from traumatic injury, regression of the primary lesion, or other external factors.

Serpiginous
A term used to describe the shape or spread of lesions that have a wavy or serpent-like pattern.

Spongiosis
A microscopic term referring to increased intercellular fluid in the epidermis (intercellular edema) that physically pulls keratinocytes away from each other accentuating where they are connected to each other by desmosomes. If severe, spongiosis will cause intraepidemal vesicles (spongiotic vesicles). This pathologic change is nonspecific but ofte...

Squamous Cell Carcinoma
A malignant neoplasm of keratinocytes derived from stratified squamous epithelium. These usually present as indurated, scaling, erythematous papules, nodules or plaques that occasionally ulcerate and bleed.

Stasis Dermatitis
Erythematous, pruritic, scaling patches on the lower extremities due to impaired venous circulation. Chronic changes in the lower extremities include edema, skin hyperpigmentation and ulcer formation.

Stevens-Johnson Syndrome
A severe form of an immune reaction in the skin that leads to a widespread eruption of a variety of tender lesions, especially bullae and

Subcutaneous Tissue
The deepest layer of skin, located between the dermis and underlying fascia.

Syphilis
Syphilis is a contagious, sexually transmitted disease caused by the spirochete Treponema pallidum. The spirochete enters through the skin or mucous membranes, on which the primary manifestations are seen.

Target Lesion
A target lesion resembles an archer

Telangectasias
Small, superficial blood vessels that become visible because they are dilated.

Telogen effluvium
A pattern of transient diffuse hair loss due to a stressful event. There is an early and excessive entry of hairs into the telogen (resting) phase and a resultant loss of these hairs two to three months later. Also known as stress-induced alopecia.

Tinea
Infection of keratinized tissues, including skin, hair, or nails, caused by a group of fungi known as dermatophytes. This term is followed by a term that refers to the body part where the infection is located. A KOH preparation will be positive.

Tinea Corporis
Fungal infection of the skin that presents as well-defined, erythematous, scaling papules or plaques. The lesions are often arranged in an annular configuration and often have an elevated, serpiginous border.

Tinea Pedis
Fungal infection of the feet that presents as scaling on the sole of the foot and scaling maceration, small vesicles, fissures, and erosions between the toes. Also known as athlete

Tinea Versicolor
Fungal infection of the skin at the stratum corneum that causes pigmentary changes and scaling in the epidermis. The lesions appear as patches with fine scale and can be pink, tan, or most commonly, white.

Tumor
Solid, firm lesions typically > 2 cm that can be above, level with, or beneath the skin surface. Also known as a mass. Skin tumors, unlike plaques, are solid lesions extending deeper and into the dermis.

Ulcer
A lesion with greater than 50% surface area ulceration.

Ulceration
A localized defect in the skin of irregular size and shape where epidermis and some dermis have been lost. Leaves a concavity in the skin.

Urticaria
An eruption of transient pruritic, elevated papules and plaques, often with erythematous, sharply-defined borders and pale centers (wheals). Each lesion resolves within twenty-four hours. Often seen as a hypersensitivity reaction to drugs, physical triggers (sun, cold, pressure, heat), and foods. Also known as hives.

Vasculitis
An inflammatory process of the blood vessels that appears as palpable purpuric papules. Also known as leukocytoclastic vasculitis (process mediated by neutrophils).

Vesicle
A small, superficial, circumscribed elevation of the skin, less than 1 cm, which contains serous fluid.

Violaceous
Violet or purple hue characteristic of inflammatory diseases located at the dermal-epidermal junction.

Viral Exanthem
A generalized eruption of erythematous macules and papules associated with systemic infection, often accompanied by fever and lymphadenopathy.

Vitiligo
An acquired condition where melanocytes are absent from affected skin. The typical lesion is a sharply demarcated, depigmented, round or oval macule or patch.

Wheal
Transient, circumscribed, elevated papules or plaques, often with erythematous borders and pale centers. These lesions are due to dermal edema and usually resolve within twenty-four hours.

Wood
Wood

Xanthoma
A yellow papule, nodule, or plaque composed of lipid-laden histiocytes (macrophages in connective tissue). Often associated with hyperlipidemia.

Xerosis
Excessive, pathological dryness of the skin or mucous membranes. Also known as xeroderma.