A cutaneous condition is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying causes and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), cause (skin conditions resulting from physical factors), and so on. Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion(s), including the location (such as arms, head, legs), symptoms (pruritus, pain), duration (acute or chronic), arrangement (solitary, generalized, annular, linear), morphology (macules, papules, vesicles), and color (red, blue, brown, black, white, yellow). The diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data. The introduction of cutaneous ultrasound has allowed the detection of cutaneous tumors, inflammatory processes, nail disorders and hair diseases.
1 Layer of skin involved
1.1 Epidermis 1.2 Dermis 1.3 Subcutaneous tissue
2 Diseases of the skin 3 History 4 Diagnoses 5 Lesions
5.1 Primary lesions 5.2 Secondary lesions 5.3 Configuration 5.4 Distribution 5.5 Other related terms
6 Histopathology 7 References
Layer of skin involved Main article: Integumentary system
The skin weighs an average of 4 kg (8.8 lb), covers an area
of 2 m2 (22 sq ft), and is made of three distinct
layers: the epidermis, dermis, and subcutaneous tissue. The two
main types of human skin are glabrous skin, the nonhairy skin on the
palms and soles (also referred to as the "palmoplantar" surfaces), and
hair-bearing skin. Within the latter type, hairs in structures
called pilosebaceous units have a hair follicle, sebaceous gland, and
associated arrector pili muscle. In the embryo, the epidermis,
hair, and glands are from the ectoderm, which is chemically influenced
by the underlying mesoderm that forms the dermis and subcutaneous
0–2 3–4 5–8 9–13 14–17 18–21 22–27 28–34 35–47 48–106
Diseases of the skin include skin infections and skin neoplasms
(including skin cancer).
Chigger bites on human skin showing characteristic welts
Macule and patch
Vesicles and bulla
Fissures, erosions and ulcers
A pustule on the cheek
Macule: A macule is a change in surface color, without elevation or depression and, therefore, nonpalpable, well or ill-defined, variously sized, but generally considered less than either 5 or 10 mm in diameter at the widest point. Patch: A patch is a large macule equal to or greater than either 5 or 10 mm across, depending on one's definition of a macule. Patches may have some subtle surface change, such as a fine scale or wrinkling, but although the consistency of the surface is changed, the lesion itself is not palpable. Papule: A papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to less than either 5 or 10 mm in diameter at the widest point. Plaque: A plaque has been described as a broad papule, or confluence of papules equal to or greater than 1 cm, or alternatively as an elevated, plateau-like lesion that is greater in its diameter than in its depth. Nodule: A nodule is morphologically similar to a papule in that it is also a palpaple spherical lesion less than 1 cm in diameter. However, it is differentiated by being centered deeper in the dermis or subcutis. Tumour: Similar to a nodule but larger than 1 cm in diameter. Vesicle: A vesicle is small blister, a circumscribed, fluid-containing, epidermal elevation generally considered less than either 5 or 10 mm in diameter at the widest point. The fluid is clear serous fluid. Bulla: A bulla is a large blister, a rounded or irregularly shaped blister containing serous or seropurulent fluid, equal to or greater than either 5 or 10 mm, depending on one's definition of a vesicle.
Pustule: A pustule is a small elevation of the skin containing cloudy or purulent material (pus) usually consisting of necrotic inflammatory cells. These can be either white or red. Cyst: A cyst is an epithelial-lined cavity containing liquid, semi-solid, or solid material. Erosion: An erosion is a discontinuity of the skin exhibiting incomplete loss of the epidermis, a lesion that is moist, circumscribed, and usually depressed. Ulcer: An ulcer is a discontinuity of the skin exhibiting complete loss of the epidermis and often portions of the dermis and even subcutaneous fat. Fissure: A fissure is a crack in the skin that is usually narrow but deep. Weal: A weal is a rounded or flat-topped, pale red papule or plaque that is characteristically evanescent, disappearing within 24 to 48 hours. The temporary raised bubble of taut skin on the site of a properly-delivered intradermal injection is also called a welt, with the ID injection process itself frequently referred to as simply "raising a weal" in medical texts. Telangiectasia: A telangiectasia represents an enlargement of superficial blood vessels to the point of being visible. Burrow: A burrow appears as a slightly elevated, grayish, tortuous line in the skin, and is caused by burrowing organisms.
Scale: dry or greasy laminated masses of keratin that represent thickened stratum corneum. Crust: dried sebum, pus, or blood usually mixed with epithelial and sometimes bacterial debris. Lichenification: epidermal thickening characterized by visible and palpable thickening of the skin with accentuated skin markings. Excoriation: a punctate or linear abrasion produced by mechanical means (often scratching), usually involving only the epidermis, but commonly reaching the papillary dermis. Induration: dermal thickening causing the cutaneous surface to feel thicker and firmer. Atrophy: refers to a loss of tissue, and can be epidermal, dermal, or subcutaneous. With epidermal atrophy, the skin appears thin, translucent, and wrinkled. Dermal or subcutaneous atrophy is represented by depression of the skin. Maceration: softening and turning white of the skin due to being consistently wet. Umbilication: formation of a depression at the top of a papule, vesicle, or pustule. Phyma: A tubercle on any external part of the body, such as in phymatous rosacea
Configuration "Configuration" refers to how lesions are locally grouped ("organized"), which contrasts with how they are distributed (see next section).
Agminate: in clusters Annular or circinate: ring-shaped Arciform or arcuate: arc-shaped Digitate: with finger-like projections Discoid or nummular: round or disc-shaped Figurate: with a particular shape Guttate: resembling drops Gyrate: coiled or spiral-shaped Herpetiform: resembling herpes Linear Mammillated: with rounded, breast-like projections Reticular or reticulated: resembling a net Serpiginous: with a wavy border Stellate: star-shaped Targetoid: resembling a bullseye Verrucous: wart-like
"Distribution" refers to how lesions are localized. They may be
confined to a single area (a patch) or may exist in several places.
Some distributions correlate with the means by which a given area
becomes affected. For example, contact dermatitis correlates with
locations where allergen has elicited an allergic immune response.
Varicella zoster virus
Symmetric: one side mirrors the other
Flexural: on the front of the fingers
Extensor: on the back of the fingers
Intertriginous: in an area where two skin areas may touch or rub
Morbilliform: resembling measles
Palmoplantar: on the palm of the hand or bottom of the foot
Periorificial: around an orifice such as the mouth
Periungual/subungual: around or under a fingernail or toenail
Blaschkoid: following the path of
Other related terms
Hyperkeratosis Parakeratosis Hypergranulosis Acanthosis Papillomatosis Dyskeratosis Acantholysis Spongiosis Hydropic swelling Exocytosis Vacuolization Erosion Ulceration Lentiginous
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and Marks' Principles of Dermatology. Saunders.
^ Lippens, S; Hoste, E; Vandenabeele, P; Agostinis, P; Declercq, W
(April 2009). "Cell death in the skin". Apoptosis. 14 (4): 549–69.
doi:10.1007/s10495-009-0324-z. PMID 19221876.
^ King, L.S. (1954). "What Is Disease?". Philosophy of Science. 21
(3): 193–203. doi:10.1086/287343.
^ Bluefarb, Samuel M. (1984). Dermatology. Upjohn Co.
^ a b c d Lynch, Peter J. (1994). Dermatology. Williams & Wilkins.
^ Tilles G, Wallach D (1989). "[The history of nosology in
dermatology]". Ann Dermatol Venereol (in French). 116 (1): 9–26.
^ Lambert WC, Everett MA (October 1981). "The nosology of
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diseases". Can Med Assoc J. 116 (10): 1165–68. PMC 1879511 .
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^ Fitzpatrick, Thomas B.; Klauss Wolff; Wolff, Klaus Dieter; Johnson,
Richard R.; Suurmond, Dick; Richard Suurmond (2005). Fitzpatrick's
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^ Werner B (August 2009). "[
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Pityriasis simplex capillitii Cradle cap
Contact dermatitis (allergic, irritant)
plants: Urushiol-induced contact dermatitis African blackwood dermatitis Tulip fingers
other: Abietic acid dermatitis Diaper rash Airbag dermatitis Baboon syndrome Contact stomatitis Protein contact dermatitis
Autoimmune estrogen dermatitis Autoimmune progesterone dermatitis
Breast eczema Ear eczema Eyelid dermatitis Topical steroid addiction Hand eczema
Chronic vesiculobullous hand eczema Hyperkeratotic hand dermatitis
Autosensitization dermatitis/Id reaction
Candidid Dermatophytid Molluscum dermatitis
Circumostomy eczema Dyshidrosis Juvenile plantar dermatosis Nummular eczema Nutritional deficiency eczema Sulzberger–Garbe syndrome Xerotic eczema
Lichen simplex chronicus/ Prurigo nodularis
Hydroxyethyl starch-induced pruritus
Senile pruritus Aquagenic pruritus
Adult blaschkitis due to liver disease
Biliary pruritus Cholestatic pruritus
substances taken internally: Bromoderma Fixed drug reaction
Nummular dermatitis Pityriasis alba Papuloerythroderma of Ofuji
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Disorders of skin appendages (L60–L75, 703–706)
thickness: Onychogryphosis Onychauxis
color: Beau's lines Yellow nail syndrome Leukonychia Azure lunula
shape: Koilonychia Nail clubbing
behavior: Onychotillomania Onychophagia
other: Ingrown nail Anonychia
Congenital onychodysplasia of the index fingers
Half and half nails
noncicatricial alopecia: Alopecia
areata totalis universalis Ophiasis
cicatricial alopecia: Pseudopelade of Brocq
Central centrifugal cicatricial alopecia
Hot comb alopecia
Perifolliculitis capitis abscedens et suffodiens
ungrouped: Triangular alopecia Frontal fibrosing alopecia Marie Unna hereditary hypotrichosis
localised generalised patterned
generalised localised X-linked
Acne vulgaris Acne conglobata Acne miliaris necrotica Tropical acne Infantile acne/Neonatal acne Excoriated acne Acne fulminans Acne medicamentosa (e.g., steroid acne) Halogen acne
Iododerma Bromoderma Chloracne
Oil acne Tar acne Acne cosmetica Occupational acne Acne aestivalis Acne keloidalis nuchae Acne mechanica Acne with facial edema Pomade acne Acne necrotica Blackhead Lupus miliaris disseminatus faciei
Granulomatous perioral dermatitis
Rhinophyma Blepharophyma Gnathophyma Metophyma Otophyma
Persistent edema of rosacea
Periorificial dermatitis Pyoderma faciale
Granulomatous facial dermatitis Idiopathic facial aseptic granuloma Periorbital dermatitis SAPHO syndrome
Epidermoid cyst Trichilemmal cyst
Hidradenitis suppurativa Recurrent palmoplantar hidradenitis Neutrophilic eccrine hidradenitis
Acrokeratosis paraneoplastica of Bazex
Bubble hair deformity
Disseminate and recurrent infundibulofolliculitis
Erosive pustular dermatitis of the scalp
Erythromelanosis follicularis faciei et colli
Granulosis rubra nasi Ross’ syndrome Anhidrosis Hyperhidrosis
Generalized Gustatory Palmoplantar
Body odor Chromhidrosis Fox–Fordyce disease
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Diseases of the skin and appendages by morphology
wart callus seborrheic keratosis acrochordon molluscum contagiosum actinic keratosis squamous-cell carcinoma basal-cell carcinoma Merkel-cell carcinoma nevus sebaceous trichoepithelioma
Freckles lentigo melasma nevus melanoma
Dermal and subcutaneous
epidermal inclusion cyst hemangioma dermatofibroma (benign fibrous histiocytoma) keloid lipoma neurofibroma xanthoma Kaposi's sarcoma infantile digital fibromatosis granular cell tumor leiomyoma lymphangioma circumscriptum myxoid cyst
With epidermal involvement
contact dermatitis atopic dermatitis seborrheic dermatitis stasis dermatitis lichen simplex chronicus Darier's disease glucagonoma syndrome langerhans cell histiocytosis lichen sclerosus pemphigus foliaceus Wiskott–Aldrich syndrome Zinc deficiency
psoriasis tinea (corporis cruris pedis manuum faciei) pityriasis rosea secondary syphilis mycosis fungoides systemic lupus erythematosus pityriasis rubra pilaris parapsoriasis ichthyosis
herpes simplex herpes zoster varicella bullous impetigo acute contact dermatitis pemphigus vulgaris bullous pemphigoid dermatitis herpetiformis porphyria cutanea tarda epidermolysis bullosa simplex
scabies insect bite reactions lichen planus miliaria keratosis pilaris lichen spinulosus transient acantholytic dermatosis lichen nitidus pityriasis lichenoides et varioliformis acuta
acne vulgaris acne rosacea folliculitis impetigo candidiasis gonococcemia dermatophyte coccidioidomycosis subcorneal pustular dermatosis
tinea versicolor vitiligo pityriasis alba postinflammatory hyperpigmentation tuberous sclerosis idiopathic guttate hypomelanosis leprosy hypopigmented mycosis fungoides
Without epidermal involvement
drug eruptions viral exanthems toxic erythema systemic lupus erythematosus
cellulitis abscess boil erythema nodosum carcinoid syndrome fixed drug eruption
urticaria erythema (multiforme migrans gyratum repens annulare centrifugum ab igne)
thrombocytopenic purpura actinic/solar purpura
disseminated intravascular coagulation vasculitis
scleroderma/morphea granuloma annulare lichen sclerosis et atrophicus necrobiosis lipoidica
telogen effluvium androgenic alopecia alopecia areata systemic lupus erythematosus tinea capitis loose anagen syndrome lichen planopilaris folliculitis decalvans acne keloidalis nuchae
onychomycosis psoriasis paronychia ingrown nail
Aphthous stomatitis oral candidiasis lichen planus leukoplakia pemphigus vulgaris mucous membrane pemphigoid cicatricial pemphigoid herpesvirus coxsackievirus syphilis systemic histoplasmosis squam