Description of Skin Lesions PDF

Description of Skin Lesions By Julia Benedetti , MD, Harvard Medical School Reviewed/Revised Jan 2024 An extensive language has been developed to standardize the description of skin lesions, including Lesion type (sometimes called primary morphology) Lesion configuration (sometimes calle...

Description of Skin Lesions By Julia Benedetti , MD, Harvard Medical School Reviewed/Revised Jan 2024 An extensive language has been developed to standardize the description of skin lesions, including Lesion type (sometimes called primary morphology) Lesion configuration (sometimes called secondary morphology) Texture Location and distribution Color Rash is a general term for a temporary skin eruption. (See also Evaluation of the Dermatologic Patient and Diagnostic Tests for Skin Disorders.) Lesion Type Cross-Section of the Skin and (Primary Skin Structures Morphology) Macules are flat, nonpalpable lesions usually < 10 mm in diameter. Macules represent a change in color and are not raised or depressed compared to the skin surface. A patch is a large macule. Examples include freckles, flat moles, tattoos, and port-wine stains, and the rashes of rickettsial infections, rubella, measles (can also have papules and plaques), and some allergic drug eruptions.  Labial... Hide Details The lesion in this photo is a macule because it is flat, nonpalpable, and of small diameter. Photo provided by Robert MacNeal, MD. Papules are elevated lesions usually < 10 mm in diameter that can be felt or palpated. Examples include nevi, warts, lichen planus, insect bites, seborrheic keratoses, actinic keratoses, some lesions of acne, and skin cancers. The term maculopapular is often loosely and improperly used to describe many erythematous rashes; because this term is nonspecific and easily misused, it should be avoided.  Hide Details Papules are elevated, usually palpable lesions < 10 mm in diameter. Lichen planus (pictured) may manifest with a papular rash. Photo provided by Thomas Habif, MD. Plaques are palpable lesions > 10 mm in diameter that are elevated or depressed compared to the skin surface. Plaques may be flat topped or rounded. Lesions of psoriasis and granuloma annulare commonly form plaques.  Hide Details Psoriasis typically manifests as plaques covered with thick, silvery, shiny scales. Plaques are elevated, palpable lesions > 10 mm in diameter. Image provided by Thomas Habif, MD. Nodules are firm papules or lesions that extend into the dermis or subcutaneous tissue. Examples include cysts, lipomas, and fibromas. Vesicles are small, fluid-filled blisters < 10 mm in diameter. Vesicles are characteristic of herpes infections, acute allergic contact dermatitis, and some autoimmune blistering disorders (eg, dermatitis herpetiformis). Skin Lesion... Hide Details Vesicles are small fluid-filled blisters < 10 mm in diameter. Dermatitis herpetiformis (pictured) typically manifests as crops of vesicles.  Photo courtesy of the Public Health Image Library of the Centers for Disease Control and Prevention. Bullae are fluid-filled blisters > 10 mm in diameter. These may be caused by burns, bites, irritant contact dermatitis or allergic contact dermatitis, and drug reactions. Classic autoimmune bullous diseases include pemphigus vulgaris and bullous pemphigoid. Bullae also may occur in inherited disorders of skin fragility. Skin Lesion... Hide Details Bullae are fluid-filled blisters > 10 mm in diameter. Bullous pemphigoid (pictured) is characterized by eruptions of tense bullae on normal-appearing or erythematous skin in older adults. Photo provided by Thomas Habif, MD. Pustules are vesicles that contain pus. Pustules are common in bacterial infections and folliculitis and may arise in some inflammatory disorders including pustular psoriasis.  Hide Details Pustules are elevated, usually yellow-topped lesions that contain pus. Scattered pustules appear on the face of this person with acne. Photo provided by Thomas Habif, MD. Urticaria (wheals or hives) is characterized by elevated lesions caused by localized edema. Wheals are pruritic and erythematous. Wheals are a common manifestation of hypersensitivity to medications, stings or bites, autoimmunity, and, less commonly, physical stimuli including temperature, pressure, and sunlight. The typical wheal lasts < 24 hours. Skin Lesion...  Hide Details Urticaria (wheals or hives) are migratory, elevated, pruritic, erythematous lesions caused by local dermal edema. Photo provided by Thomas Habif, MD. Scale is heaped-up accumulations of horny epithelium (stratum corneum) that occur in disorders such as psoriasis, seborrheic dermatitis, and fungal infections. Pityriasis rosea and chronic dermatitis of any type may be scaly. Skin Lesion (Scales) Hide Details Scales are heaped-up accumulations of horny epithelium. Scaling is a characteristic feature of many dermatophytoses, including tinea capitis, resulting in the large bald patches. In this image, scale is especially noticeable at the nape of the neck.  Image provided by Thomas Habif, MD. Crusts (scabs) consist of dried serum, blood, or pus. Crusting can occur in inflammatory or infectious skin diseases (eg, impetigo). Erosions are open areas of skin that result from loss of part or all of the epidermis. Erosions can be traumatic or can occur with various inflammatory or infectious skin diseases. An excoriation is a linear erosion caused by scratching, rubbing, or picking. Ulcers result from loss of the epidermis and at least part of the dermis. Causes include venous stasis dermatitis, physical trauma with or without vascular compromise (eg, caused by decubitus ulcers or peripheral arterial disease), infections, and vasculitis. Petechiae are nonblanchable punctate foci of hemorrhage. Causes include platelet abnormalities (eg, thrombocytopenia, platelet dysfunction), vasculitis, and infections (eg, meningococcemia, Rocky Mountain spotted fever, other rickettsioses). Purpura is a larger area of hemorrhage that may be palpable. Purpura does not blanch. Palpable purpura is considered the hallmark of leukocytoclastic vasculitis. Purpura may indicate a coagulopathy. Large areas of purpura may be called ecchymoses or, colloquially, bruises. Atrophy is thinning of the skin, which may appear dry and wrinkled, resembling cigarette paper. Atrophy may be caused by chronic sun exposure, aging, and some inflammatory and neoplastic skin diseases, including cutaneous T-cell lymphoma and lupus erythematosus. Atrophy also may result from long-term use of potent topical corticosteroids. Scars are areas of fibrosis that replace normal skin after injury. Some scars become hypertrophic or thickened and raised. Keloids are hypertrophic scars that extend beyond the original wound margin. Telangiectases are foci of small, permanently dilated blood vessels that may occur in areas of sun damage, rosacea, systemic diseases (especially systemic sclerosis), or inherited diseases (eg, ataxia- telangiectasia, hereditary hemorrhagic telangiectasia) or after long- term therapy with topical fluorinated corticosteroids. Telangiectasias Hide Details Telangiectasias are small, dilated blood vessels; they are most often idiopathic. Photo provided by Thomas Habif, MD. Lesion Configuration (Secondary Morphology) Configuration is the shape of single lesions and the arrangement of clusters of lesions. Linear lesions take on the shape of a straight line and are suggestive of some forms of contact dermatitis, linear epidermal nevi, and lichen striatus. Excoriations resulting from scratching are typically linear. Annular lesions are rings with central clearing. Examples include granuloma annulare, some drug eruptions, some dermatophyte infections (eg, tinea [ringworm]), and secondary syphilis. Hide Details This photo shows the typical skin lesions of granuloma annulare. The lesions manifest as rings with central clearing. Photo provided by Thomas Habif, MD. Nummular lesions are circular or coin-shaped; an example is nummular dermatitis (nummular eczema). Target (bull’s-eye or iris) lesions appear as rings with central Nummular Dermatitis duskiness and are classic for erythema multiforme.  MION/PHANIE/SCIENCE PHOTO LIBRARY Target...  Hide Details Target lesions (sometimes called iris lesions) manifest as annular lesions with a violaceous center and pink halo separated by a pale ring. Such lesions, which are typical of erythema multiforme, are distributed symmetrically. Photo provided by Robert MacNeal, MD. Serpiginous lesions have linear, branched, and curving elements. Examples include some fungal and parasitic infections (eg, cutaneous larva migrans). Reticulated lesions have a lacy or networked pattern. Examples include cutis marmorata and livedo reticularis. Livedo Reticularis  Hide Details This photo shows the lacy pattern of erythema typical of livedo reticularis. © Springer Science+Business Media Herpetiform describes grouped papules or vesicles arranged like those of a herpes simplex infection. Herpetiform... Hide Details Herpetiform lesions manifest as grouped papules or vesicles in a formation resembling those of a herpes simplex infection. This photo shows clusters of vesicles on erythematous bases that are highly characteristic. Photo provided by Robert MacNeal, MD. Zosteriform describes lesions clustered in a dermatomal distribution similar to those of herpes zoster. Texture of Skin Lesions Some skin lesions have a visible or palpable texture that suggests a diagnosis. Verrucous lesions have an irregular, pebbly, or rough surface. Examples include warts and seborrheic keratoses. Lichenification is thickening of the skin with accentuation of normal skin markings; it results from repeated scratching or rubbing. Skin Lesion... Hide Details Lichenification is thickening of the skin with accentuation of normal skin markings; it is a result of chronic scratching or rubbing, which in this patient occurred during the chronic phase of atopic dermatitis.  Image provided by Thomas Habif, MD. Induration, or deep thickening of the skin, can result from edema, inflammation, or infiltration, including by cancer. Indurated skin has a hard, resistant feeling. Induration is characteristic of panniculitis, some skin infections, and cutaneous metastatic cancers. Umbilicated lesions have a central indentation and are usually viral. Examples include molluscum contagiosum and herpes simplex. Xanthomas, which are yellowish, waxy lesions, may be idiopathic or may occur in patients who have lipid disorders. Xanthelasma of the Eyelid Hide Details This photo shows yellow-white plaques on the upper medial eyelids in a patient with hypercholesterolemia. Xanthelasma are not specific for familial hypercholesterolemia. © Springer Science+Business Media Location and Distribution of Skin Lesions It is important to note whether Lesions are single or multiple. Particular body parts are affected (eg, palms or soles, scalp, mucosal membranes). Distribution is random or patterned, symmetric or asymmetric. Lesions are on sun-exposed or protected skin. Although few patterns are pathognomonic, some are consistent with certain diseases. Psoriasis frequently affects the scalp, extensor surfaces of the elbows and knees, umbilicus, and the gluteal cleft. Lichen planus frequently arises on the wrists, forearms, genitals, and lower legs. Vitiligo may be patchy and isolated or may group around the distal extremities and face, particularly around the eyes and mouth. Discoid lupus erythematosus has characteristic lesions on sun- exposed skin of the face, especially the forehead, nose, and the conchal bowl of the ear. Hidradenitis suppurativa involves skin containing a high density of apocrine glands, including the axillae, groin, and under the breasts. Color of Skin Lesions When examining the color of skin, health care professionals should note that the natural color of a patient's skin can change the appearance of colors. Red skin (erythema) can result from many different inflammatory or infectious diseases. Cutaneous tumors are often pink or red. Superficial vascular lesions such as port-wine stains may appear red. Orange skin is most often seen in hypercarotenemia, a usually benign condition of carotene deposition after excess dietary ingestion of beta- carotene. Yellow skin is typical of jaundice, xanthelasmas and xanthomas, and pseudoxanthoma elasticum. Green fingernails suggest Pseudomonas aeruginosa infection. Violet skin may result from cutaneous hemorrhage or vasculitis. Vascular lesions or tumors, such as Kaposi sarcoma and hemangiomas, can appear purple. A lilac color of the eyelids or heliotrope eruption is characteristic of dermatomyositis. Shades of blue, silver, and gray can result from deposition of medications or metals in the skin, including minocycline, amiodarone, and silver (argyria). Ischemic skin appears purple to gray in color. Deep dermal nevi appear blue. Black skin lesions may be melanocytic, including nevi and melanoma. Black eschars are collections of dead skin that can arise from infarction, which may be caused by infection (eg, anthrax, angioinvasive fungi including Rhizopus, meningococcemia), calciphylaxis, arterial insufficiency, or vasculitis. Other Clinical Signs of Skin Lesions Dermatographism (dermographism) is the appearance of an urticarial wheal after focal pressure (eg, stroking or scratching the skin) in the distribution of the pressure. Up to 5% of patients may exhibit this sign, which is a form of physical urticaria.  Dermatographism Hide Details Dermatographism, or skin-writing, may occur when the skin is lightly scratched and results in raised red lines. © Springer Science+Business Media Darier sign refers to rapid swelling of a lesion when stroked. It occurs in patients with urticaria pigmentosa or mastocytosis. Nikolsky sign is epidermal shearing that occurs with gentle Darier Sign lateral pressure on seemingly uninvolved skin in patients with toxic epidermal necrolysis and some autoimmune bullous diseases. Auspitz sign is the appearance of pinpoint bleeding after scale is removed from plaques in psoriasis. Koebner phenomenon describes the development of lesions within areas of trauma (eg, © SPRINGER SCIENCE+BUSINESS caused by scratching, rubbing, or MEDIA injury). Psoriasis frequently exhibits this phenomenon, as may lichen planus, often resulting in linear lesions. Copyright © 2024 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved. Evaluation of the Diagnostic Tests for Skin Dermatologic Patient Disorders