Dermatology Terminology

Acne Vulgaris A chronic disorder of the pilosebaceous apparatus associated with an increase in sebum secretion. It is characterized by open comedones (blackheads), closed comedones (whiteheads), and pustular nodules. The cause is unknown, but heredity and age are predisposing factors.

Acral Relating to or affecting the peripheral parts, e.g., limbs, fingers, ears, etc.

Acute febrile neutrophilic dermatosis (Sweet's Syndrome) Condition characterized by large, rapidly extending, erythematous, tender plaques on the upper body usually accompanied by fever and dermal infiltration of neutrophilic leukocytes. It occurs mostly in middle-aged women, is often preceded by an upper respiratory infection, and clinically resembles erythema multiforme. Sweet's syndrome may herald the appearance of leukemia.

Annular Ringshaped.

Anterior in human anatomy, denoting the front surface of the body; Axillary Folds one of the folds of skin and muscular tissue bounding the axilla.

Aspiration The act of inhaling.

Atopic Dermatitis A chronic inflammatory genetically determined disease of the skin marked by increased ability to form reagin (IgE), with increased susceptibility to allergic rhinitis and asthma, and hereditary disposition to a lowered threshold for pruritus. It is manifested by lichenification, excoriation, and crusting, mainly on the flexural surfaces of the elbow and knee. In infants it is known as infantile eczema.

Atrophic Denoting atrophy.

Atrophy A wasting of tissues, organs, or the entire body, as from death and reabsorption of cells, diminished cellular proliferation, decreased cellular volume, pressure, ischemia, malnuturition, lessened function, or hormonal changes.

Axilla; Fossa Axillaris Axillary cavity; armpit; space below the shoulder joint.

Basal Cell Carcinoma A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). More than 95% of these carcinomas occur in patients over 40. They develop on hairbearing skin, most commonly on sunexposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p. 1471)

Basement membrane zone An amorphous extracellular layer closely applied to the basal surface of epithelium and also investing muscle cells, fat cells, and Schwann cells.

Beryllium Beryllium. An element with the atomic symbol Be, atomic number 4, and atomic weight 9.01218. Short exposure to this element can lead to a type of poisoning known as BERYLliOSIS.

Pemphigoid, Bullous A chronic and relatively benign subepidermal blistering disease usually of the elderly and without histopathologic acantholysis.

Candidiasis infection with a fungus of the genus Candida. It is usually a superficial infection of the moist cutaneous areas of the body, and is generally caused by C. albicans; it most commonly involves the skin (dermatocandidiasis), oral mucous membranes (thrush, def. 1), respiratory tract (bronchocandidiasis), and vagina (vaginitis). Rarely there is a systemic infection or endocarditis. Called also moniliasis, candidosis, oidomycosis, and, formerly, blastodendriosis. Dorland's Illustrated Medical Dictionary 27th edition; entry for candidiasis. Infection with a fungus of the genus CANDIDA. It is usually a superficial infection of the moist areas of the body and is generally caused by CANDIDA ALBICANS.

Circular In the shape of a circle, round.

Collagen The major protein of the white fibers of connective tissue, cartilage, and bone which is insouble in water, but can be altered to easily degestible, soluble gelatins by boiling in water, dilute acids, or alkalies. In anatomy, a structure comparable to a shell in shape, as the auricle or pinna of the ear or a turbinated bone in the nose.

Contralateral Relating to the opposite side, as when pain is felt or paralysis occurs on the side opposite to that of the lesion.

Crusting To form a hard outer layer or covering (scab).

Cutaneous T-cell lymphoma Relating to the skin. Ordinarily malignant neoplasms of lymphoid and reticuloendothelial tissues which present as apparently circumscribed solid tumors composed of cells, or histiocytes.

Cuticles The layer, chitinous in some invertebrates, which occurs on the surface of epithelial cells.

Deepseated Placed or originating far beneath the surface; Pustule small circumscribed elevations of the skin, containing purulent material.

Depigmented Loss of pigment which may be partial or complete.

Dermal relating to the skin; Metabolic sum of the chemical changes occurring in tissue, consisting of anabolism and catabolism; Deposits sediments or precipitates.

Desmoglein A group of related glycoproteins which are major components of the desmosomal complex that forms specialized cellcell junctions in epithelia and cardiac muscle. One of these, the product of the DSG1 gene, is the autoantigen in human endemic pemphigus folicaceus, and another, the produce of the DSG3 gene, is the autoantigen in human pemphigus vulgaris.

Desmosomes Bridge corpuscle; a site of adhesion between two epithelial cells, consisting of a dense attachment plaque separated from a similar structure in the other cell by a thin layer of extracellular material.

Desquamation The shedding of the cuticle in scales or of the outer layer of any surface.

Dyskeratosis Premature keratinization of epithelial cells that have not reached the keratinizing surface layer; dyskeratotic cells are generally rounded and separated from adjacent cells by apoptosis.

Edematous Marked by edema (an accumulation of an excessive amount of watery fluid in cells, tissues, or serous cavities).

Epidermal relating to the epidermis; Atrophy A wasting of tissues, organs, or the entire body, as from death and reabsorption of cells, diminished cellular proliferation, decreased cellular volume, pressure, ischemia, malnuturition, lessened function, or hormonal changes.

hyperplasia An increase in the number of cells in a tissue or organ, not due to tumor formation. It differs from HYPERtrOPHY, which is an increase in bulk without an increase in the number of cells

Erythematous relating to or marked by erythema (inflammatory redness of the skin); Eruption breaking out, expecially the appearance of lesions on the skin.

Eschar A thick, coagulated crust or slough which develops following a thermal burn or chemical or physical cauterization of the skin.

Excoriations A scratch mark; a linear break in the skin surface, usually coverd with blood or serous crusts.

Exudate Any fluid that has exuded out of a tissue or its capillaries, more specifically because of injury or inflammation in which case is characteristically high in protein and white blood cells.

Execudative Relating to the process of exudation or to an exudate.

Fissure A deep furrow, cleft, or slit.

Flaccid Relaxed, flabby, or without tone.

Follicular Realting to a follicle or follicles (more or less spherical masses of cells usually containing a cavity); Orifices any aperture or opening.

Genetic mosaic Relating to 1)genetiecs;2) otogeny. The juxtaposition in an organism of genetically different tissues, resulting from somatic mutation, an anomaly of chromosome division resulting in two or more types of cells containing different numbers of chromosomes.

Granular composed of or resembling granules or granulations (grainlike particles, a minute discrete mass); particles with strong affinity for nuclear stains, seen in many bacterial species; Cell the smallest unit of living structure capapble of independent existence, composed of a membraneenclosed mass of protoplasm and containing a nucleus or nucleoid.

Granulating Forming into grains or granules (grainlike particles, minute destrete masses).

Grouped A number of similar or related objects.

Herpes any inflammatory skin disease caused by a herpesvirus and characterized by the formation of clusters of small vesicles. When used alone, the term may refer to herpes simplex or to herpes zoster. Dorland's Illustrated Medical Dictionary 27th edition; entry for herpes.

Herpes Simplex a group of acute infections caused by herpes simplex virus type 1 or type 2, characterized by the development of one or more small fluidfilled vesicles with a raised erythematous base on the skin or mucous membrane, and occurring as a primary infection or recurring because of reactivation of a latent infection. Type 1 infections usually involve nongenital regions of the body, whereas in type 2 infections the lesions are primarily seen on the genital and surrounding areas. Precipitating factors include fever, exposure to cold temperature or to ultraviolet rays, sunburn, cutaneous or mucosal abrasions, emotional stress, and nerve injury. Dorland's Illustrated Medical Dictionary 27th edition; entry for herpes simplex. A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluidfilled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. (Dorland, 27th ed.)

Hyperkeratosis Hypertrophy of the horny layer of the epidermis.

Hyperpigmented Superpigmentation; an excess of pigment in a tissue or part.

Ichthyosis Any of several generalized skin disorders characterized by dryness, roughness, and scaliness, due to hypertrophy of the stratum corneum epidermis. Most are genetic, but some are acquired, developing in association with other systemic disease or genetic syndrome.

Impetigo 1. a contagious pyoderma caused by direct inoculation of group A streptococci or Staphylococcus aureus into superficial cutaneous abrasions or compromised skin, most commonly seen in children, usually located on the face, especially about the nose and mouth, and characterized by the presence of discrete fragile vesicles surrounded by an erythematous border that become pustular and rupture to discharge a thin, ambercolored seropurulent fluid that dries and forms a thick yellowish crust; the pustules may spread peripherally with central healing, evolving into annular, circinate, or gyrate patterns. Called also i. contagiosa, i. vulgaris, and streptococcal i. 2. i. bullosa. Dorland's Illustrated Medical Dictionary 27th edition; entry for impetigo. A common superficial bacterial infection caused by STAPHYLOCOCCUS AUREUS or group A betahemolytic streptococci. Characteristics include pustular lesions that rupture and discharge a thin, ambercolored fluid that dries and forms a crust. This condition is commonly located on the face, especially about the mouth and nose.

Infiltrated Permeating or penetrating into a substance, cell, or tissue; said of gases, fluids, or matter held in solution; injection of solution into tissues, as in infiltration anesthesia.

Intertriginous Characterized by or realted to intertrigo (Dermatitis occurring between folds or juxtaposed surfaces of the skin caused by sweat retention, moisture, warmth, and concomitant overgrowth of resident microorganisms).

Kaposi's sarcoma A multifocal malignant or benign neoplasm of primitive vasoformative tissue, occuring in the skin and sometimes in lymph nodes or viscera; consists of spindle cells and small vascular spaces, frequently infiltrated by hemosiderin-pigmented macrophages.

Keloid a sharply elevated, irregularlyshaped, progressively enlarging scar due to the formation of excessive amounts of collagen in the corium during connective tissue repair. Dorland's Illustrated Medical Dictionary 27th edition; entry for keloid. A sharply elevated, irregularly shaped, progressively enlarging scar resulting from formation of excessive amounts of collagen in the dermis during connective tissue repair. It is differentiated from a hypertrophic scar (CICAtrIX, HYPERtrOPHIC) in that the former does not spread to surrounding tissues.

Keratin A scleroprotein or albuminoid present largely in cuticular structures, it contains a relatively large amount of sulfur, is insoluble in the gastric juices, and is sometimes used for coating enteric pills that are intended to be dissolved only in the intestine.

Leprosy A chronic granulomatous infection caused by MYCOBACTERIUM LEPRAE. lesions are manifested in the skin, the mucous membranes, and the peripheral nerves. Two polar or principal types are lepromatous and tuberculoid

Leukemia a progressive, malignant disease of the bloodforming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemia is classified clinically on the basis of (1) the duration and character of the diseaseacute or chronic; (2) the type of cell involvedmyeloid (myelogenous), lymphoid (lymphogenous), or monocytic; (3) increase or nonincrease in the number of abnormal cells in the bloodleukemic or aleukemic (subleukemic). Dorland's Illustrated Medical Dictionary 27th edition; entry for leukemia

Lichenification hypertrophy of the epidermis, resulting in thickening of the skin with exaggeration of the normal skin markings, giving the skin a leathery barklike appearance, which is caused by prolonged rubbing or scratching. It may arise on seemingly normal skin, or it may develop at the site of another pruritic cutaneous disorder. Dorland's Illustrated Medical Dictionary 27th edition; entry for lichenification

linear epidermal nevus Pertaining to or resembling a line. Relating to the epidermis. Birthmark; a circumscribed malformation of the skin, especially if colored by hyperpigmentation or increased vascularity.
Lines of Blaschko These lines refer to the patterns in which nevi and related dermatological pathologies are distributed or develop. These lesions develop along certain preferred cutaneous pathways. These do not appear to correspond to vascular or neural elements of the skin and may be related to early developmental boundaries of a "mosaic" nature.

Lipoma a benign tumor usually composed of mature fat cells. At times the tumor may be composed partly or entirely of fetal fat cells (hibernoma). Dorland's Illustrated Medical Dictionary 27th edition; entry for lipoma. Also, Dorland, 27th ed.

Lupus A form of cutaneous tuberculosis. It is seen predominantly in women and typically involves the nasal, buccal, and conjunctival mucosa.

Lymphoma a group of malignant neoplasms characterized by the proliferation of cells native to the lymphoid tissues, i.e., lymphocytes, histiocytes, and their precursors and derivatives. The group is divided into two major clinicopathologic categories: Hodgkin's disease and nonHodgkin's lymphoma. Dorland's Illustrated Medical Dictionary 27th edition; entry for malignant lymphoma A general term for various neoplastic diseases of the lymphoid tissue

A patch of skin altered in color but usu. not elevated that is a characteristic feature of various diseases (as smallpox)

Melanin Pigments causing darkness in skin, hair, feathers, etc. They are irregular polymeric structures and are divided into three groups: allomelanins in the plant kingdom and eumelanins and phaeomelanins in the animal kingdom

mel'anosit, Pigment cell of the skin; melanodendrocyte; a cell located at the dermoepedermal junction having branching processes by means of which melanosomes are transferred to epidermal cells, resulting in pigmentation.

Melanoma a tumor arising from the melanocytic system of the skin and other organs. When used alone, the term refers to malignant melanoma. Dorland's Illustrated Medical Dictionary 27th edition; entry for melanoma A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p. 2445)

Mycobacterial or deep fungal infection Relating to a genus of aerobic, nonmotile bacteria containing Grampositive, acidfast, sleder, stright or slightly curved rods. Or relating to fungus. Multiplication of parasitic organisms within the body.

Myelodysplastic Syndromes Conditions in which the bone marrow shows qualitative and quantitative changes suggestive of a preleukemic process, but having a chronic course that does not necessarily terminate as acute leukemia.

Neocrotic Pertaining to or affected by necrosis. Neocrosis Pathologic death of one or more cells, or of a portion of tissue or organ, resulting from irreversible damage.

Neovascular channels Literally "new blood vessels." Refers to the prominent telangiectases associated with angiogenic factorsecreting proliferative neoplasms.

Neovascular Proliferation of blood vessels in tissue not normally containing them, or proliferation of blood vessels of a different kind than usual in tissue.

nu'rofibro'mato'sis, von Recklinghausen's disease; neuromatosis; molluscum fibroscum; multiple neurofibromas; small, discrete, pigmented skin lesions (cafe'aulait spots) that develop in infancy or early childhood, followed by development of multiple subcutaneous neurofibromas that may slowly increase in number and size over many years.

Panatrophy Atrophy of all the parts of astructure, such as the body.

Papillomatosis The development of numerous papillomas (papillary tumor); Papillary projections of the epidermis forming a microscopically udulating surface.

Papular Relating to papules (a small, circumcribed, solid elevation on the skin involving predominantly the epidermis or the dermis.)

Patulous Patent (open or exposed).

Pemphigus Group of chronic blistering diseases characterized histologically by acantholysis and blister formation within the epidermis.

Perioral area Circumoral; around the mouth.

Petechiae Minute hemorrhagic spots, of pinpoint to pinhead size, in the skin which are not blanched by diascopy.

Pitted nails Small punctate depressions on the surface of the nail plate due to defective nail formation.

Plaque A patch or small differentiated area on a body surface or on the cut surface of an organ such as the brain.

Polycyclic Having two or more rings or whorls.

Polymorphonuclear leukocytes Neutrophils Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.

Posterio axillary folds Posterior in human anatomy, denoting the back surface of the body. Axillary Folds one of the folds of skin and muscular tissue bounding the axilla.

Proximal: Nearest the trunk or the point of origin, said of part of a limb, of an artery or a nerve etc. Nail Folds: wall of mail; the fold of skin overlapping the lateral and proximal margins of the nail.

Psoriasis A common genetically determined, chronic, inflammatory skin disease characterized by rounded erythematous, dry, scaling patches. The lesions have a predilection for nails, scalp, genitalia, extensor surfaces, and the lumbosacral region. Accelerated epidermopoiesis is considered to be the fundamental pathologic feature in psoriasis.

Punched out Refers to an ulcer with a clearly defined border, as if made with a sharp tool.

Purpuric Relating to or affected with purpura (a condition characterized by hemorrahage into the skin).

pustules Small circumscribed elevations of the skin, containing purulent material.

Reticular Relating to a reticulum ( a fine network formed by cells); Dermal relating to the skin; Plexus a network or interjoining of nerves and blood vessels or of lymphatic vessles.

Rolled up Heaped up; sausage shaped; in the shape of a roll.

Sarcoidosis A chronic, progressive, systemic granulomatous reticulosis of unknown etiology, involving almost any organ or tissue, including the skin, lungs, lymph nodes, liver, spleen, eyes, and small bones of the hands and feet. It is characterized histologically by noncaseating epithelioid cell tubercles in all affected organs. Laboratory findings may show hypercalcemia and hypergammaglobulinemia, diminished or absent reactivity to tuberculin, and a positive Kveim reaction in most active cases.

Sarcoma A connective tissue neoplasm formed by proliferation of mesodermal cells; it is usually highly malignant

Scale A small thin plate of horny epithelium, resembling a fish scale, cast off from the skin.

Shiny Luster, polish, gloss.

silica Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.

Solitary Without others, single, alone.

Staphylococcus aureus Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and peritoneum of warmblooded animals. They may cause a wide range of infections and intoxications.

Subcorneal Occurring between the cornified cell layers and the granular cell layer of the epidermis.

Symmetrical Equality or correspondence in form of parts distributed around a center or axis, at the extemities or poles, or on the opposite sides of any body.

Superficial fungal Infection 1. invasion and multiplication of microorganisms in body tissues, which may be clinically inapparent or result in local cellular injury due to competitive metabolism, toxins, intracellular replication, or antigenantibody response. The infection may remain localized, subclinical, and temporary if the body's defensive mechanisms are effective. A local infection may persist and spread by extension to become an acute, subacute, or chronic clinical infection or disease state. A local infection may also become systemic when the microorganisms gain access to the lymphatic or vascular system. 2. an infectious disease. Cf. infestation. Dorland's Illustrated Medical Dictionary 27th edition; entry for infection.

Tense Stretched tight; strained, taut.

Tinea barbae tinea involving the bearded area of the face and neck, occurring in three types: in the inflammatory type, usually caused by Trichophyton mentagrophytes and T. verrucosum, the typical lesions are kerionlike swellings and nodular swellings and may produce marked crusting; in the ringworm type, the annular lesions resemble those of ringworm of nonhairy skin; and in the sycosiform type (t. sycosis); caused usually by Trichophyton violaceum and less often by T. rubrum, the lesions are follicular pustules, each containing a hair that may break off and leave a stub or become epilated. Called also barber's itch and ringworm of the beard. Dorland's Illustrated Medical Dictionary 27th edition; entry for tinea barbae.

Tragus A tonguelike projection of the cartilage of the auricle in front of the opening of the external acoustic meatus and continuous with the cartilage of this canal.

Transudation Passage of a fluid or solute through a membrane by a hydrostatic or osmotic pressure gradient.

Tuberculosis Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM

Ulcer A lesion on the surface of the skin or a mucous surface, caused by superficial loss of tissue, usually with inflammation.

Umbilicated Of navel shape; pitlike; dimpled.

Umbilication A pit or navellike depression; formation of a depression at the apex of a papule, vesicle, or pustule.

Varicosity A varix (a dilated vein; an enlarged and tortuous vein, artery, or lymphatic vessel) or varicose condition.

Vasodilation Phlebarteriectasia of the blood vessels.

Vesicles A small circumscribed elevation of the skin containing fluid; a small sac containing liquid or gas.

Vesicular Relating to a vesicle; characterized by or containing vesicles.

Vitiligo a usually progressive, chronic pigmentary anomaly of the skin manifested by depigmented white patches that may be surrounded by a hyperpigmented border; it is associated with a dominantly inherited predisposition, and it has been speculated that autoimmune mechanisms are involved in the etiology. Cf. leukoderma and piebaldism. Dorland's Illustrated Medical Dictionary 27th edition; entry for vitiligo. A disorder consisting of areas of macular depigmentation, commonly on extensor aspects of extremities, on the face or neck, and in skin folds. Age of onset is often in young adulthood and the condition tends to progress gradually with lesions enlarging and extending until a quiescent state is reached.

Wheal, Welt a circumscribed, evanescent area of edema of the skin, appearing as an urticarial lesion, slightly redened, often changing in size and shape and extending to adjacent areas, and usually accompainied by intense itching.

Xerosis dry skin

Zirconium a rather rare metallic element; symbol Zr; atomic number, 40; atomic weight, 91.22; chiefly obtained from a mineral called zircon. Dorland's Illustrated Medical Dictionary 27th edition; entry for zirconium.