Macules - flat circumscribed changes of the skin. They may be of any size, have no palpable manifestations, and are neither elevated nor depressed in reference to the skin. Macules may appear as areas of hyperpigmentation, hypopigmentation or vascular abnormality. Are usually rounded, but may be oval or irregular, and may be distinct or may fade into flat nevi, cafe au lait spots, areas of vitiligo or hypopigmentation, and flat vascular lesions such as telangiectases or capillary hemangiomas of the salmon patch or port wine type.

Papules - circumscribed elevated lesions of one to five millimeters in diameter. Examples: elevated nevi, verrucae, molluscum contagiosum, and individual lesions of lichen planus.

Nodules - circumscribed, elevated, usually solid lesions that measure roughly between 0.5 and 2 cm in diameter. May be located only in the epidermis or may extend deeper into the dermis or subcutaneous tissue. Examples: fibromas, neurofibromas, xanthomas, intradermal or compound nevi, lesions of erythema nodosum, and various benign or malignant growths.

Plaques - elevated disc-shaped lesions that occupy a relatively larger area. Frequently are formed by a confluence of papules and may be seen in psoriasis, lichen simplex chronicus (neurodermatitis) or lesions of planus.

Tumors - larger and deeper circumscribed solid lesions of the skin or subcutaneous tissue. May be benign or malignant processes and include lesions such as lipomas, strawberry or cavernous hemangiomas and various neoplastic growths.

Wheals - are a distinctive type of solid elevation formed by local, superficial, transient edema. White to pink or pale red in color, compressible, and evanescent, they often disappear within a period of hours. They vary in size and shape and may be seen in dermographism, insect bites, and various forms of urticaria.

Vesicles - are sharply circumscribed, elevated fluid-containing lesions that measure 0.5 cm in diameter or less. Examples are lesions of herpes, dyshidrosis, pompholyx, varicella, and contact dermatitis.

Bullae - are larger circumscribed, elevated fluid-containing lesions over 0.5 cm in diameter. They may be seen in burns, contact dermatitis, pemphigus, and epidermolysis bullosa.

Pustules - are circumscribed elevations that contain a purulent exudate. They may be bacterial in nature as in pyoderma (impetigo) or may be sterile as in pustular psoriasis, bromoderma or smallpox.

Comedones - are plugged secretions of horny material retained within a pilosebaceous follicle. They may be flesh-colored closed comedones (white-heads) or slightly raised brown or black open comedones (black heads). Closed comedones, in contrast to open comedones, may be difficult to visualize. They appear as pale, slightly elevated small papules without a clinically visible orifice. Since closed comedones are the precursors of the papules, pustules, cysts, or nodules of acne, they are of considerable clinical importance.

Burrows - are linear lesions produced by tunneling of an animal parasite in the stratum corneum. Burrows may be seen in scabies or cutaneous larva migrans (creeping eruption) and, when present, are highly characteristic and diagnostic of these disorders.

Telangiectasia - refers to a relatively permanent dilatation of superficial venules, capillaries, or arterioles of the skin. They may be seen in actinically damaged skin, rosacea, radiodermatitis, hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease), essential telangiectasia, angiokeratomas, lesions of lupus erythematosus, lipomas, and basal cell epitheliomas, and when present in the cuticular region (cuticular telangiectasia) are a patholognomonic sign of connective tissue, such as lupus erythematosus, dermatomyositis, or scleroderma.

Crusts - are the result of dried remains of serum, blood, pus, or exudate overlying areas of lost or damaged epidermis. They may be seen in third-degree burns, in lesions of weeping eczematous dermatitis, or as dried honey-colored lesions of impetigo.

Scales - are formed by an accumulation of compact desquamation layers of stratum corneum. A result of abnormal keratinization and exfoliation of cornified keratinocytes they may be greasy and yellowish in color (seborrheic dermatitis), silvery and mica-like (psoriasis), fine and barely visible (pityriasis alba or tinea versicolor), or large, adherent, and lamellar (in various forms of ichthyosis).

Fissures - is a dry or moist linear, often painful, cleavage in cutaneous surface that results from marked drying and long-standing inflammation, thickening, and loss of elasticity of the integument. Fissures frequently appear in chronic dermatoses and calluses of the hands and feet.

Erosions - are moist, slightly depressed versicular lesions in which part or all of the epidermis has been lost or denuded. Since erosions do not extend into the underlying dermis or subcutaneous tissue, healing occurs without subsequent scar formation.

Excoriations - refers to a traumatized or abraded (usually self-induced) superficial loss of skin caused by scratching, rubbing, or scrubbing of the cutaneous surface. Excoriations are seen in pruritic disorders such as atopic dermatitis, neurotic excoriations, contact dermatitis, fiberglass dermatitis, prurigo nodularis, icterus, varicella, papular urticaria, dermatitis herpetiformis, scabies, pediculosis, and acne exoriee.

Ulcerations - also know as Cutaneous ulcers, are the result of necrosis of the epidermis and part or all of the dermis and/or the underlying subcutaneous tissue. Ulcers may occur as the result of bacterial, parasitic or fungal infection, tissue infarction, halogenoderma, scleroderma, ecthyma, frostbite, sickle cell disease, and benign or neoplastic necrosis of tissue (as in decubitus ulcers, basal cell epithelioma, or reticulum cell sarcoma).

Atrophy - refers to cutaneous changes that result in depression of the epidermis, dermis or both. Epidermal atrophy is characterized by thin, almost translucent epidermis, a loss of the normal skin markings, and wrinkling when subjected to lateral pressure or pinching of the affected area. In dermal atrophy, there is a depression of the skin without change in color or skin markings.

Scars - also known as cicatrices, are permanent fibrotic skin changes, that develop following damage to the dermis. Initially pink or violaceous in color, as the color fades they remain as permanent white, shiny sclerotic areas. Although fresh scars often tend to be hypertrophic, with passage of time (frequently six months to a year) they usually contract and become less apparent. Hypertrophic scars must be differentiated from keloids, which represent an exaggerated connective tissue response to tissue injury.

Keloids - are pink, smooth, and rubbery and often are traversed by telangiectatic vessels. They tend to increase in size long after healing has taken place and can be differentiated from hypertrophic scars by the fact that the surface of keloidal scars tend to be proliferated beyond the area of the original wound.

Annular, circinate or ring-shaped lesions - a number of dermatologic entities assume annular shapes and are interpreted as "ring-worm" or superficial fungal infections. Although tinea is indeed one of the common annular dermatoses of childhood, other disorders that must be included in the differential diagnosis of ringed lesions include pityriasis rosea, seborrheic dermatitis, granuloma annulare, psoriasis, erythema multiforme, erythema annulare centrifugum, erythema chronicum migrans, secondary syphillis, sarcoidosis, urticaria, pityriasis alba, and tinea versicolor.

Arciform or arcuate lesions - refer to lesions that assume arc-like configurations. Arciform lesions may be seen in erythema multiforme, urticaria, and pityriasis rosea.

Confluent lesions - lesions that tend to join or run together are said to be confluent. Confluence of lesions is seen in childhood exanthems, rhus dermatitis, erythema multiforme, and urticaria.

Dermatomal lesions - lesions localized into a dermatome supplied by one or more dorsal ganglia are said to be dermatomal in nature. Prominent examples of this type of distribution include lesions of herpes zoster and segmental vitiligo.

Discoid lesions - this term is used to discribe lesions that are solid, moderately raised, and disc shaped. Although frequently utilized to differentiate cutaneous forms from systemic forms of lupus erythematosus, since one cannot determine from the clinical or histologic examination of a discoid lesion whether or not there is systemic involvement, a more appropriate term would be cutaneous rather than discoid.

Discrete lesions - individual lesions that tend to remain separated and distinct are said to be discrete in nature. Discrete lesions appear in a variety of conditions and although perhaps of descriptive value, this term is neither characteristic nor diagnostic of any specific disorder.

Eczematoid or eczematous disorders - these terms are adjectives relating to eczema and suggest inflammation with a tendency to thickening, oozing, vesiculation, or crusting.

Grouping or clustering - are characteristic of vesicles of herpes simplex or herpes zoster, insect bites, lymphangioma circumscriptum, contact dermatitis, and bullous dermatosis of childhood.

Guttate lesions - Guttate or drop-like lesions are characteristic of flares of psoriasis in children and adolescents that follow an acute upper respiratory infection, usually, but not necessarily, streptococcal in nature.

Gyrate lesions - refers to twisted, coiled or spiral-like lesions, such as may be seen in patients with urticaria and erythema annulare centrifugum.

Iris lesions - Iris or target-like lesions are concentric ringed lesions characteristic of erythema multiforme of both regular and bullous (Steven-Johnson) varieties.

Keratosis (keratotic) - the term keratosis (plural keratoses) refers to circumscribed patches of horny thickening, as seen in seborrheic or actinic (solar) keratoses, keratosis pilaris, and keratosis follicularis (Darier's disease). Keratotic is an adjective pertaining or relating to keratosis and frequently refers to the horny thickening of the skin seen in chronic dermatitis and callus formation.

Koebner phenomenon (isomorphic response) - refers to an isomorphic response with the appearance of lesions along the site of injury. This phenomenon may be seen with warts, molluscum contagiosum, rhus dermatitis (poison ivy), psoriasis, lichen planus, lichen nitidus, pityriasis rubra pilaris, and keratosis follicularis (Darier's disease).

Linear disorders - lesions in a linear or band-like configuration appear in the form of a line or stripe and may be seen in linear nevi (nevus unius lateris), linear morphea or scleroderma (the coupe de sabre deformity), or as lesions of lichen striatus.

Moniliform lesions - refers to a banded or necklace-like appearance. This is seen in monilethrix, a hair deformity characterized by beaded nodularities along the hair shaft.

Multiforme lesions - refers to disorders in which more than one variety or shape of cutaneous lesions occurs. The most common manifestation of this configuration is typified by the varied lesions seen in patients with erythema multiforme, early Henoch-Schonlein purpura, and polymorphous light eruption.

Polycyclic - refers to oval lesions containing more than one ring. This frequently is seen in patients with urticara.

Serpiginous - this term describes the shape or spread of lesions in a serpentine or snake-like configuration. This term is used to describe lesions of cutaneous larva migrans (creeping eruption) and elastosis perforans serpiginosa.

Umbilicated lesions - terms umbilication and umbilicated refer to lesions that are depressed or shaped like an umbilicus or navel. Examples include lesions of molluscum contagiosum, varicella, vaccinia, variola, herpes zoster, and Kaposi's varicelliform eruption.

Universal (universalis) - terms universal and universalis imply widespread disorders affecting the entire skin (as in alopecia universalis).

Zosteriform - is a descriptive term that implies a linear arrangement along a nerve. This configuration is typified by lesions of herpes zoster and linear forms of keratosis follicularis (zosteriform Darier's disease).