Dermatology Terminology

Abscess a localized collection of pus caused by suppuration buried in tissues, organs, or confined spaces. Dorland's Illustrated Medical Dictionary 27th edition; entry for abscess.

Acantholysis Separation of the prickle cells of the stratum spinosum of the epidermis, resulting in atrophy of the prickle cell layer. It is seen in diseases such as pemphigus vulgaris and keratosis follicularis.

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

Alopecia Absence of the hair from areas where it is normally present.

Annular Ring-shaped

bullae Visible accumulations of fluid within or beneath the epidermis.

Carbuncle An infection of cutaneous and subcutaneous tissue that consists of a cluster of boils. Commonly, the causative agent is STAPHYLOCOCCUS AUREUS. Carbuncles produce fever, leukocytosis, extreme pain, and prostration.

Chronic discoid lupus erythematosus A form of lupus erythematosus in which only cutaneous lesions are present; these commonly appear on the face and are atrophic plaques with erythema, hyperkeratosis, follicular plugging, and telangiectasia.

Circumscribe To encircle so as to touch at as many points as possible.

Confluent Joining or running together.

Discoid Shaped like a disc

Discoid lupus erythematosus See 'chronic discoid lupus erythematosus'.

Domeshaped In the form of a dome; swelled out like a dome.

Epidermal hyperplasia Relating to the epidermis. Numerical or quantitiative hypertrophy: increase in number of cells in a tissue or organ, excluding tumor formation, whereby the bulk of the part or organ may be increased.

Epidermis Nonvascular layer of the skin. It is made up, from within outward, of five layers: 1) basal layer (stratum basale epidermidis); 2) spinous layer (stratum spinosum epidermidis); 3) granular layer (stratum granulosum epidermidis); 4) clear layer (stratum lucidum epidermidis); and 5) horny layer (stratum corneum epidermidis).

Exanthema Diseases in which skin eruptions or rashes are a prominent manifestation. Classically, six such diseases were described with similar rashes; they were numbered in the order in which they were reported. Only the fourth (Duke's disease), fifth (ERYTHEMA INFECTIOSUM), and sixth (EXANTHEMA SUBITUM) .
Erythema Abnormal redness of the skin due to capillary congestion (as in inflammation)

Fibroblasts Connective tissue cells which differentiate into chondroblasts, collagenoblasts, and osteoblasts.

Fibrotic Pertaining to or characterized by fibrosis, the formation of fibrous tissue, usually as a repairative or reactive process; the term is not used with reference to formation of fibrous tissue that is a normal consitituent of an organ or tissue..

Flexor A muscle of which the action is to flex a joint.

Furuncle, Furunculosis An infection where furuncles are present over a period of weeks to months. Species of STAPHYLOCOCCUS are usually the causative agents.

Generalized Pustular Psoriasis An extensive exacerbation of psoriasis with pustule formation in the normal and psoriatic skin, fever, and granulocytosis. (psoriasis a condition characterized by the eruption of circumscribed, descrete and confluent, reddish, silvery scaled maculopapules.) (pustule a small circumscribed elevation of the skin, containing purulent material).

Gram stain A method for differential staining of bacteria; smears are fixed by flaming, stained in a solution of crystal violet, treated with iodine solution, rinsed, decolorized, and then counterstained with safranin O.

Granulating; Granulation Tissue the newly formed vascular tissue normally produced in the healing of wounds of soft tissue and ultimately forming the cicatrix; it consists of small, translucent, red, nodular masses or granulations that have a velvety appearance.

Granulomatous inflammation Having the characteristics of a granuloma. Granuloma: Indefinite term applied to nodular inflammatory lesions, usually small or granular, firm, persistent, and containing compactly grouped mononuclear phagocytes.

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 fluid filled 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 eactivation of a latent infection.

Herpetiform Resembling herpes

Keratosis Any horny growth such as a wart or callus.

Hyper- and Hypopigmentation A condition caused by a deficiency in melanin formation or a loss of preexisting melanin or melanocytes. It can be complete or partial and may result from trauma, inflammation, and certain infections.

Irregular Lacking perfect symmetry or evenness

Keratoderma blenorrhagicum Pustules and crusts associated with Reiter's disease.

Kerion celsi A granulomatous secondarily infected lesion complicating fungal infection of the hair.

Lesion The state of the organism when function is impaired.

Lichenification A multifocal malignant neoplasm of primitive vasoformative tissue, occuring in the skin and sometimes in lymph nodes or vicera, consisteing of spindle cells an irregular small vascular spaces frequently infiltrated by hemosiderinpigmented macrophages and extravasated red cells.

Lichenization; leathery induration and thickening of the skin with hyperkeratosis, due to a chronic inflammation caused by scratching or longcontinued irriation.

Membranes Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.

Neurofibromatosis A disorder that has been classed into at least two autosomal dominant disorders chiefly characterized by the presence of multiple neurofibromas. As many as six additional types have been proposed to characterize what appear to be clinically distinct entities within this group.

Nevus 1. any congenital lesion of the skin; a birthmark. 2. a circumscribed stable malformation of the skin and occasionally of the oral mucosa, which is not due to external causes and therefore presumed to be of hereditary origin. The excess (or deficiency) of tissue may involve epidermal, connective tissue, adnexal, nervous, or vascular elements; a cutaneous hamartoma. Dorland's Illustrated Medical Dictionary 27th edition; entry for nevus. A circumscribed stable malformation of the skin and occasionally of the oral mucosa, which is not due to external causes and therefore presumed to be of hereditary origin. The excess (or deficiency) of tissue may involve epidermal, connective tissue, adnexal, nervous, or vascular elements.

Nodule A small node.

Papule A small, circumscribed, solid elevation on the skin involving predominantly the epidermis or the dermis, depending on the type of pathological process.

Patch A small circumscribed area differing in color or structure from the surrounding area.

Periorificial The area surrounding the normal connective tissues immediately around the teeth.

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

Poikiloderma A condition in which the skin wastes away or atrophies.

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.

Pus a liquid inflammation product made up of cells (leukocytes) and a thin fluid called liquor puris. Dorland's Illustrated Medical Dictionary 27th edition; entry for pus.

Pyoderma Any purulent skin disease.

Reiter's syndrome The association of urethritis, iridocyclitis, and arthritis, sometimes with diarrhea. One or more of these conditions may recur at intervals of months or years, but the arthritis may be persistent.

Scars; also Cicatrix The formation of new tissue in the process of wound healing.

Superficial Fungal Infection Cursory; not thorough; pertaining to or situated near the surface. Fungal fungous. Infection multiplication of parasictic organisms within the body.

Telangiectasis WHAT: Telangiectasia. Telangiectasia: the visible dilatation of superficial cutaneous blood vessels. WHY: Telangiectasia may be noted in the connective tissue diseases. In discoid and systemic lupus erythematosus, dermatomyositis and systemic sclerosis, they are the result of microvascular damage. The visible vessels are believed to be normal ones which have dilated (shunts) in response to obliteration of other small vessels. HOW: Ascertained by physical examination. The affected blood vessels collapse upon pressure and fill slowly when pressure is released. Telangiectasia result from a permanent increase in the diameter of small blood vessels, making them grossly visible. They should be distinguished from rapidly filling spider angiomata with central arterioles. Locations to be checked specifically in examination of patients with connective tissue disease are the digits, face, lips, tongue and other oral mucous membranes. REFS: Dictionary of the Rheumatic Diseases, Volume I: Signs and Symptoms. American Rheumatism Association, 1982. (Descriptor #101). Permanent dilation of preexisting blood vessels (capillaries, arterioles, venules) creating small focal red lesions, usually in the skin or mucous membranes. The lesion may present as a coarse or fine red line or as a punctum with radiating limbs. (From Dorland, 27th ed)

Tumor An abnormal mass of tissue that grows more rapidly than normal and continues to grow after the stimuli which initiated the new growth cease..

Ulcer A lesion on the surface of the skin or a mucous surface, produced by the sloughing of inflammatory necrotic tissue.

Urticaria A vascular reaction of the skin characterized by erythema and wheal formation due to localized increase of vascular permeability. The causative mechanism may be allergy, infection, or stress.

Vasculitis Inflammation of a blood vessel.

Vasodilation Dilation of the blood vessels without anatomic change, for which DILATATION, PATHOLOGIC or ANEURYSM (or specific aneurysm) is used. The condition of an anatomical structure's being dilated beyond normal dimensions.

Vegetating Growing or increasing in size, as a wart or other abnormal growth.

Verrucous Resembling a wart; denoting wartlike elevations.

Violaceous Showing a purple discoloration.

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.

Warty Relating to or covered with warts.