Cosmetic Science/Skin Conditions

thumb | In vitro testing uses cell cultures. A skin condition, also known as 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.Miller Jeffrey H. Marks James G. Lookingbill and Marks' Principles of Dermatology Saunders 2006 1-4160-3185-5 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).Bluefarb, Samuel M. Dermatology Upjohn Co 1984 0-89501-004-6 registration https://archive.org/details/dermatology00samu 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).Fitzpatrick, Thomas B. Klauss Wolff Wolff, Klaus Dieter Johnson, Richard R. Suurmond, Dick Richard Suurmond Fitzpatrick's color atlas and synopsis of clinical dermatology McGraw-Hill Medical Pub. Division 2005 0-07-144019-4 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.Xiaowei Xu Elder, David A. Rosalie Elenitsas Johnson, Bernett L. Murphy, George E. Lever's Histopathology of the Skin Lippincott Williams & Wilkins Hagerstwon, MD 2008 978-0-7817-7363-8 The introduction of cutaneous ultrasound has allowed the detection of cutaneous tumors, inflammatory processes, nail disorders and hair diseases. Layer of skin involved The skin weighs an average of 4 kg lb on, covers an area of 2 m2 sqft on, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are glabrous skin, the non-hairy skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin.Burns, Tony; et al. (2006) Rook's Textbook of Dermatology CD-ROM. Wiley-Blackwell. 1-4051-3130-6. Within the latter type, hairs in structures called pilosebaceous units have a hair follicle, sebaceous gland, and associated arrector pili muscle.Paus R, Cotsarelis G The biology of hair follicles N Engl J Med 341 7 491–97 1999 10441606 10.1056/NEJM199908123410706 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 tissues. Epidermis alt=3D medical illustration showing major layers of skin|thumb|381x381px|3D medical illustration showing major layers of skinThe epidermis is the most superficial layer of skin, a squamous epithelium with several strata: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Nourishment is provided to these layers via diffusion from the dermis, since the epidermis is without direct blood supply.Skin Anatomy http://emedicine.medscape.com/article/1294744-overview Medscape 3 June 2013 The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. Of these, keratinocytes are the major component, constituting roughly 95% of the epidermis. This stratified squamous epithelium is maintained by cell division within the stratum basale, in which differentiating cells slowly displace outwards through the stratum spinosum to the stratum corneum, where cells are continually shed from the surface. In normal skin, the rate of production equals the rate of loss; about two weeks are needed for a cell to migrate from the basal cell layer to the top of the granular cell layer, and an additional two weeks to cross the stratum corneum.Bolognia, Jean L. Dermatology Mosby St. Louis 2007 978-1-4160-2999-1 etal Dermis The dermis is the layer of skin between the epidermis and subcutaneous tissue, and comprises two sections, the papillary dermis and the reticular dermis. The superficial papillary dermis interdigitates with the overlying rete ridges of the epidermis, between which the two layers interact through the basement membrane zone. Structural components of the dermis are collagen, elastic fibers, and ground substance also called extra fibrillar matrix.Rapini, Ronald P. Practical dermatopathology Elsevier Mosby 2005 0-323-01198-5 Within these components are the pilosebaceous units, arrector pili muscles, and the eccrine and apocrine glands. The dermis contains two vascular networks that run parallel to the skin surface—one superficial and one deep plexus—which are connected by vertical communicating vessels.Grant-Kels, JM Color Atlas of Dermatopathology (Dermatology: Clinical & Basic Science) Informa Healthcare 2007 163 978-0-8493-3794-9 The function of blood vessels within the dermis is fourfold: to supply nutrition, to regulate temperature, to modulate inflammation, and to participate in wound healing. Subcutaneous tissue The subcutaneous tissue is a layer of fat between the dermis and underlying fascia. This tissue may be further divided into two components, the actual fatty layer, or panniculus adiposus, and a deeper vestigial layer of muscle, the panniculus carnosus. The main cellular component of this tissue is the adipocyte, or fat cell.Lynch, Peter J. Dermatology Williams & Wilkins 1994 0-683-05252-7 The structure of this tissue is composed of septal (i.e. linear strands) and lobular compartments, which differ in microscopic appearance. Functionally, the subcutaneous fat insulates the body, absorbs trauma, and serves as a reserve energy source. Diseases of the skin Diseases of the skin include skin infections and skin neoplasms (including skin cancer). History In 1572, Geronimo Mercuriali of Forlì, Italy, completed la De morbis cutaneis (translated "On the diseases of the skin"). It is considered the first scientific work dedicated to dermatology. Diagnoses The physical examination of the skin and its appendages, as well as the mucous membranes, forms the cornerstone of an accurate diagnosis of cutaneous conditions.Callen, Jeffrey Color atlas of dermatology W.B. Saunders Philadelphia 2000 0-7216-8256-1 Most of these conditions present with cutaneous surface changes termed "lesions," which have more or less distinct characteristics. Often proper examination will lead the physician to obtain appropriate historical information and/or laboratory tests that are able to confirm the diagnosis. Upon examination, the important clinical observations are the (1) morphology, (2) configuration, and (3) distribution of the lesion(s). With regard to morphology, the initial lesion that characterizes a condition is known as the "primary lesion," and identification of such a lesions is the most important aspect of the cutaneous examination. Over time, these primary lesions may continue to develop or be modified by regression or trauma, producing "secondary lesions." However, with that being stated, the lack of standardization of basic dermatologic terminology has been one of the principal barriers to successful communication among physicians in describing cutaneous findings.Wolff, Klaus Dieter Fitzpatrick's Dermatology in General Medicine McGraw-Hill Medical 2008 978-0-07-146690-5 etal Nevertheless, there are some commonly accepted terms used to describe the macroscopic morphology, configuration, and distribution of skin lesions, which are listed below.James, William D. Andrews' Diseases of the Skin: Clinical Dermatology Saunders Elsevier 2006 0-7216-2921-0 etal Lesions Primary lesions vertical thumb TrombiculosisSores.jpg Chigger bites on human skin showing characteristic welts Macule and Patch.svg Macule and patch Papule and Plaque.svg Papule and plaque Nodules.svg Nodules Vesicles and Bulla.svg Vesicles and bulla Ulcers, fissures, and erosions.svg Fissures, erosions and ulcers Teenager-with-acne.jpg 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 5Fitzpatrick, Thomas B. Fitzpatrick's color atlas and synopsis of clinical dermatology Klauss Wolff Wolff, Klaus Dieter Johnson, Richard R. Suurmond, Dick Richard Suurmond McGraw-Hill Medical Pub. Division 2005 0-07-144019-4 New York 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 10 mm, or alternatively as an elevated, plateau-like lesion that is greater in its diameter than in its depth. NoduleNodule: A nodule is morphologically similar to a papule in that it is also a palpable spherical lesion less than 10 mm in diameter. However, it is differentiated by being centered deeper in the dermis or subcutis. Tumour: Similar to a nodule but larger than 10 mm in diameter. VesicleVesicle: A vesicle is small blister,Elsevier Elsevier Dorland's Illustrated Medical Dictionary Elsevier http://dorlands.com/ . 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. BullaBulla: 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. PustulePustule: 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. Wheal WealWheal: A wheal 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 wheal" 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. Secondary lesions 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. Erosion: An erosion is a discontinuity of the skin exhibiting incomplete loss of the epidermis,Robbins and Cotran pathologic basis of disease Cotran, Ramzi S. Kumar, Vinay Fausto, Nelson Nelso Fausto Robbins, Stanley L. Abbas, Abul K. Elsevier Saunders 2005 0-7216-0187-1 St. Louis, Mo a lesion that is moist, circumscribed, and usually depressed.https://basicmedicalkey.com/alterations-in-the-integumentary-system/ Alterations in the Integumentary System Copstead Lee-Ellen C. Diestelmeier Ruth E. 2016-09-03 Basicmedical Key en-US 2019-07-01 Diestelmeier Michael R. Excoriation: a punctate or linear abrasion produced by mechanical means (often scratching), usually involving only the epidermis, but commonly reaching the papillary dermis. 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. 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 constantly wet. UmbilicationUmbilication: formation of a depression at the top of a papule, vesicle, or pustule.Description of Skin Lesions http://www.merckmanuals.com/professional/dermatologic_disorders/approach_to_the_dermatologic_patient/description_of_skin_lesions.html The Merk Manual 3 June 2013 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). 22em 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 "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 is known to recur (after its initial presentation as chicken pox) as herpes zoster ("shingles"). Chicken pox appears nearly everywhere on the body, but herpes zoster tends to follow one or two dermatomes; for example, the eruptions may appear along the bra line, on either or both sides of the patient. 30em Generalized 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 together 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 Blaschko's lines in the skin Photodistributed: in places where sunlight reaches Zosteriform or dermatomal: associated with a particular nerve Other related terms 30em Collarette Comedo Confluent Eczema (a type of dermatitis) Evanescent (lasting less than 24 hours) Granuloma Livedo Purpura Erythema (redness) Horn (a cell type) Poikiloderma Histopathology 22em Hyperkeratosis Parakeratosis Hypergranulosis Acanthosis Papillomatosis Dyskeratosis Acantholysis Spongiosis Hydropic swelling Exocytosis Vacuolization Erosion Ulceration Lentiginous References