Skin condition

"Pustule" redirects here. It is not to be confused with Boil.

Skin condition

3D medical illustration showing major layers of skin
Specialty| Dermatology
Causes| Sun exposure, vitamin deficiencies, substance usage, poor hygiene, cancers

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, nails, and related muscle and glands.[1] The major function of this system is as a barrier against the external environment.[2]

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).[3][4] While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described.[5] Classification of these conditions often presents many nosological challenges, since underlying causes and pathogenetics are often not known.[6][7] 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.[8][9]

Clinically, the diagnosis of any particular skin condition begins by gathering pertinent information of the presenting skin lesion(s), including: location (arms, head, legs); symptoms (pruritus, pain); duration (acute or chronic); arrangement (solitary, generalized, annular, linear); morphology (macules, papules, vesicles); and color (red).[10] Some diagnoses may also require a skin biopsy which yields histologic information[11][12] that can be correlated with the clinical presentation and any laboratory data.[13][14] The introduction of cutaneous ultrasound has allowed the detection of cutaneous tumors, inflammatory processes, and skin diseases.[15]

## Contents

* 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 See also
* 8 References
* 9 External links

## Layer of skin involved[edit | edit source]

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.[1] 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.[16] Within the latter type, hairs in structures called pilosebaceous units have a hair follicle, sebaceous gland, and associated arrector pili muscle.[17] 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.[18][19][20]

### Epidermis[edit | edit source]

Main article: Epidermis (skin)

The 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.[21] Nourishment is provided to these layers via diffusion from the dermis, since the epidermis is without direct blood supply.[22] 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.[16] 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.[16] 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.[23]

### Dermis[edit | edit source]

Main article: 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.[24] The superficial papillary dermis interdigitates with the overlying rete ridges of the epidermis, between which the two layers interact through the basement membrane zone.[24] Structural components of the dermis are collagen, elastic fibers, and ground substance also called extra fibrillar matrix.[24] Within these components are the pilosebaceous units, arrector pili muscles, and the eccrine and apocrine glands.[21] 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.[21][25] 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.[26][27]

### Subcutaneous tissue[edit | edit source]

Main article: Subcutaneous tissue

The subcutaneous tissue is a layer of fat between the dermis and underlying fascia.[5] 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.[16] The main cellular component of this tissue is the adipocyte, or fat cell.[5] The structure of this tissue is composed of septal (i.e. linear strands) and lobular compartments, which differ in microscopic appearance.[21] Functionally, the subcutaneous fat insulates the body, absorbs trauma, and serves as a reserve energy source.[5]

## Diseases of the skin[edit | edit source]

For a list, see List of skin conditions.

Diseases of the skin include skin infections and skin neoplasms (including skin cancer).[28]

## History[edit | edit source]

See also: History of dermatology

In 1572, Geronimo Mercuriali of Forlì, Italy, completed De morbis cutaneis ('On the diseases of the skin'). It is considered the first scientific work dedicated to dermatology.

## Diagnoses[edit | edit source]

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.[29] Most of these conditions present with cutaneous surface changes termed "lesions," which have more or less distinct characteristics.[30] Often proper examination will lead the physician to obtain appropriate historical information and/or laboratory tests that are able to confirm the diagnosis.[29] Upon examination, the important clinical observations are the (1) morphology, (2) configuration, and (3) distribution of the lesion(s).[29] 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.[30] Over time, these primary lesions may continue to develop or be modified by regression or trauma, producing "secondary lesions".[1] 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.[21] Nevertheless, there are some commonly accepted terms used to describe the macroscopic morphology, configuration, and distribution of skin lesions, which are listed below.[30]

## Lesions[edit | edit source]

### Primary lesions[edit | edit source]

Chigger bites on human skin showing characteristic welts

Macule and patch

Papule and plaque

Nodules

Vesicles and bulla

Fissures, erosions and ulcers

A pustule on the cheek

Relative incidence of skin cysts

* Macule: A macule is a change in surface color, without elevation or depression, so nonpalpable, well or ill-defined,[10] variously sized, but generally considered less than either 5[10] or 10 mm in diameter at the widest point.[30]
* Patch: A patch is a large macule equal to or greater than either 5 or 10 mm across,[30] depending on one's definition of a macule.[1] 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.[29]
* Papule: A papule is a circumscribed, solid elevation of skin, varying in size from less than either 5[10] or 10 mm in diameter at the widest point.[30]
* Plaque: A plaque has been described as a broad papule, or confluence of papules equal to or greater than 10 mm,[30] or alternatively as an elevated, plateau-like lesion that is greater in its diameter than in its depth.[29]
* Nodule: 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.
* Tumor: Similar to a nodule, but it is larger than 10 mm in diameter.[citation needed]
* Vesicle: A vesicle is small blister,[31] a circumscribed, epidermal elevation generally considered less than either 5[10] or 10 mm in diameter at the widest point.[30]
* Bulla: A bulla is a large blister,[31] a rounded or irregularly shaped blister equal to or greater than either 5[10] or 10 mm,[30] depending on one's definition of a vesicle.[1]
* Pustule: A pustule is a small elevation of the skin usually consisting of necrotic inflammatory cells.[30]
* Cyst: A cyst is an epithelial-lined cavity. [10]
* Wheal: 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 skin on the site of a properly delivered intradermal (ID) injection is also called a welt, with the ID injection process itself frequently referred to as simply "raising a wheal" in medical texts.[10]
* Welts: Welts occur as a result of blunt force being applied to the body with elongated objects without sharp edges.
* Telangiectasia: A telangiectasia represents an enlargement of superficial blood vessels to the point of being visible.[29]
* Burrow: A burrow appears as a slightly elevated, grayish, tortuous line in the skin, and is caused by burrowing organisms.[29][30]

### Secondary lesions[edit | edit source]

* Scale: Dry or greasy laminated masses of keratin,[30] they represent thickened stratum corneum.[29]
* Crust: Dried sebum usually mixed with epithelial and sometimes bacterial debris[10]
* Lichenification: Epidermal thickening characterized by visible and palpable thickening of the skin with accentuated skin markings[1]
* Erosion: An erosion is a discontinuity of the skin exhibiting incomplete loss of the epidermis,[32] a lesion that is moist, circumscribed, and usually depressed.[21][33]
* Excoriation: A punctate or linear abrasion produced by mechanical means (often scratching), usually involving only the epidermis, but commonly reaching the papillary dermis[30][33]
* Ulcer: An ulcer is a discontinuity of the skin exhibiting complete loss of the epidermis and often portions of the dermis.[32][33]
* Fissure is a lesion in the skin that is usually narrow but deep.[29][33]
* Induration is dermal thickening causing the cutaneous surface to feel thicker and firmer.[29]
* Atrophy refers to a loss of skin, and can be epidermal, dermal, or subcutaneous.[30] With epidermal atrophy, the skin appears thin, translucent, and wrinkled.[29] Dermal or subcutaneous atrophy is represented by depression of the skin.[29]
* Maceration: softening and turning white of the skin due to being consistently wet.
* Umbilication is formation of a depression at the top of a papule, vesicle, or pustule.[34]
* Phyma: A tubercle on any external part of the body, such as in phymatous rosacea

### Configuration[edit | edit source]

"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 or Verruciform: wart-like

### Distribution[edit | edit source]

"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.[citation needed]

* 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[edit | edit source]

* 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[edit | edit source]

* Hyperkeratosis
* Parakeratosis
* Hypergranulosis
* Acanthosis
* Papillomatosis
* Dyskeratosis
* Acantholysis
* Spongiosis
* Hydropic swelling
* Exocytosis
* Vacuolization
* Erosion
* Ulceration
* Lentiginous

## See also[edit | edit source]

* List of dermatology terminology

## References[edit | edit source]

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Miller, Jeffrey H.; Marks, James G. (2006). Lookingbill and Marks' Principles of Dermatology. Saunders. ISBN 1-4160-3185-5.
2. ↑ 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. S2CID 13058619.
3. ↑ King, L.S. (1954). "What Is Disease?". Philosophy of Science. 21 (3): 193–203. doi:10.1086/287343. S2CID 120875348.
4. ↑ Bluefarb, Samuel M. (1984). Dermatology. Upjohn Co. ISBN 0-89501-004-6.
5. ↑ 5.0 5.1 5.2 5.3 Lynch, Peter J. (1994). Dermatology. Williams & Wilkins. ISBN 0-683-05252-7.
6. ↑ Tilles G, Wallach D (1989). "[The history of nosology in dermatology]". Ann Dermatol Venereol (in français). 116 (1): 9–26. PMID 2653160.
7. ↑ Lambert WC, Everett MA (October 1981). "The nosology of parapsoriasis". J. Am. Acad. Dermatol. 5 (4): 373–95. doi:10.1016/S0190-9622(81)70100-2. PMID 7026622.
8. ↑ Jackson R (1977). "Historical outline of attempts to classify skin diseases". Can Med Assoc J. 116 (10): 1165–68. PMC 1879511. PMID 324589.
9. ↑ Copeman PW (February 1995). "The creation of global dermatology". J R Soc Med. 88 (2): 78–84. PMC 1295100. PMID 7769599.
10. ↑ 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 Wolff, Klaus; Johnson, Richard Allen; Suurmond, Richard (2005). Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology (5th ed.). McGraw-Hill Medical Pub. Division. ISBN 0-07-144019-4.
11. ↑ Werner B (August 2009). "[Skin biopsy and its histopathologic analysis: Why? What for? How? Part I]". An Bras Dermatol (in português). 84 (4): 391–95. doi:10.1590/s0365-05962009000400010. PMID 19851671.
12. ↑ Werner B (October 2009). "[Skin biopsy with histopathologic analysis: why? what for? how? part II]". An Bras Dermatol (in português). 84 (5): 507–13. doi:10.1590/S0365-05962009000500010. PMID 20098854.
13. ↑ Xiaowei Xu; Elder, David A.; Rosalie Elenitsas; Johnson, Bernett L.; Murphy, George E. (2008). Lever's Histopathology of the Skin. Hagerstwon, MD: Lippincott Williams & Wilkins. ISBN 978-0-7817-7363-8.
14. ↑ Weedon's Skin Pathology, 2-Volume Set: Expert Consult – Online and Print. Edinburgh: Churchill Livingstone. 2009. ISBN 978-0-7020-3941-6.
15. ↑ Alfageme, Fernando; Cerezo, Eugenio; Roustan, Gaston (April 2015). "Real-Time Elastography in Inflammatory Skin Diseases: A Primer". Ultrasound in Medicine & Biology. 41 (4): S82–S83. doi:10.1016/j.ultrasmedbio.2014.12.341.
16. ↑ 16.0 16.1 16.2 16.3 Burns, Tony; et al. (2006) Rook's Textbook of Dermatology CD-ROM. Wiley-Blackwell. ISBN 1-4051-3130-6.
17. ↑ Paus R, Cotsarelis G (1999). "The biology of hair follicles". N Engl J Med. 341 (7): 491–97. doi:10.1056/NEJM199908123410706. PMID 10441606.
18. ↑ Goldsmith, Lowell A. (1983). Biochemistry and physiology of the skin. Oxford University Press. ISBN 0-19-261253-0.
19. ↑ Fuchs E (February 2007). "Scratching the surface of skin development". Nature. 445 (7130): 834–42. Bibcode:2007Natur.445..834F. doi:10.1038/nature05659. PMC 2405926. PMID 17314969.
20. ↑ Fuchs E, Horsley V (April 2008). "More than one way to skin ". Genes Dev. 22 (8): 976–85. doi:10.1101/gad.1645908. PMC 2732395. PMID 18413712.
21. ↑ 21.0 21.1 21.2 21.3 21.4 21.5 Wolff, Klaus Dieter; et al. (2008). Fitzpatrick's Dermatology in General Medicine. McGraw-Hill Medical. ISBN 978-0-07-146690-5.
22. ↑ "Skin Anatomy". Medscape. Archived from the original on 12 May 2013. Retrieved 3 June 2013.
23. ↑ Bolognia, Jean L.; et al. (2007). Dermatology. St. Louis: Mosby. ISBN 978-1-4160-2999-1.
24. ↑ 24.0 24.1 24.2 Rapini, Ronald P. (2005). Practical dermatopathology. Elsevier Mosby. ISBN 0-323-01198-5.
25. ↑ Grant-Kels, JM (2007). Color Atlas of Dermatopathology (Dermatology: Clinical & Basic Science). Informa Healthcare. p. 163\. ISBN 978-0-8493-3794-9.
26. ↑ Ryan, T (1991). "Cutaneous Circulation". In Goldsmith, Lowell A (ed.). Physiology, biochemistry, and molecular biology of the skin (2nd ed.). New York: Oxford University Press. p. 1019\. ISBN 0-19-505612-4.
27. ↑ Swerlick, RA; Lawley, TJ (January 1993). "Role of microvascular endothelial cells in inflammation". J. Invest. Dermatol. 100 (1): 111S–115S. doi:10.1038/jid.1993.33. PMID 8423379.
28. ↑ Rose, Lewis C. (1998-09-15). "Recognizing Neoplastic Skin Lesions: A Photo Guide". American Family Physician. 58 (4): 873–84, 887–8. PMID 9767724. Archived from the original on 2013-11-02. Retrieved 3 June 2013.
29. ↑ 29.00 29.01 29.02 29.03 29.04 29.05 29.06 29.07 29.08 29.09 29.10 29.11 Callen, Jeffrey (2000). Color atlas of dermatology. Philadelphia: W.B. Saunders. ISBN 0-7216-8256-1.
30. ↑ 30.00 30.01 30.02 30.03 30.04 30.05 30.06 30.07 30.08 30.09 30.10 30.11 30.12 30.13 James, William D.; et al. (2006). Andrews' Diseases of the Skin: Clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
31. ↑ 31.0 31.1 Elsevier, Dorland's Illustrated Medical Dictionary, Elsevier, archived from the original on 2014-01-11, retrieved 2022-04-09.
32. ↑ 32.0 32.1 Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease. St. Louis, Mo: Elsevier Saunders. ISBN 0-7216-0187-1.
33. ↑ 33.0 33.1 33.2 33.3 Copstead, Lee-Ellen C.; Diestelmeier, Ruth E.; Diestelmeier, Michael R. (2016-09-03). "Alterations in the Integumentary System". Basicmedical Key. Archived from the original on 2019-07-01. Retrieved 2019-07-01.
34. ↑ "Description of Skin Lesions". The Merck Manual. Archived from the original on 21 May 2013. Retrieved 3 June 2013.

## External links[edit | edit source]

* v
* t
* e

Dermatitis and eczema

Atopic dermatitis|

* Besnier's prurigo

Seborrheic dermatitis|

* 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

Eczema|

* 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

Pruritus/Itch/
Prurigo|

* Lichen simplex chronicus/Prurigo nodularis

* by location: Pruritus ani
* Pruritus scroti
* Pruritus vulvae
* Scalp pruritus

* Drug-induced pruritus
* Hydroxyethyl starch-induced pruritus
* Senile pruritus
* Aquagenic pruritus
* Aquadynia

* Adult blaschkitis
* due to liver disease
* Biliary pruritus
* Cholestatic pruritus
* Prion pruritus
* Prurigo pigmentosa
* Prurigo simplex
* Puncta pruritica
* Uremic pruritus

Other|

* substances taken internally: Bromoderma
* Fixed drug reaction

* Nummular dermatitis
* Pityriasis alba
* Papuloerythroderma of Ofuji

* v
* t
* e

Disorders of skin appendages

Nail|

* thickness: Onychogryphosis
* Onychauxis

* color: Beau's lines
* Yellow nail syndrome
* Leukonychia
* Azure lunula

* shape: Koilonychia
* Nail clubbing

* behavior: Onychotillomania
* Onychophagia

* other: Ingrown nail
* Anonychia

* ungrouped: Paronychia
* Acute
* Chronic
* Chevron nail
* Congenital onychodysplasia of the index fingers
* Green nails
* Half and half nails
* Hangnail
* Hapalonychia
* Hook nail
* Ingrown nail
* Lichen planus of the nails
* Longitudinal erythronychia
* Malalignment of the nail plate
* Median nail dystrophy
* Mees' lines
* Melanonychia
* Muehrcke's lines
* Nail–patella syndrome
* Onychoatrophy
* Onycholysis
* Onychomadesis
* Onychomatricoma
* Onychomycosis
* Onychophosis
* Onychoptosis defluvium
* Onychorrhexis
* Onychoschizia
* Platonychia
* Pincer nails
* Plummer's nail
* Psoriatic nails
* Pterygium inversum unguis
* Pterygium unguis
* Purpura of the nail bed
* Racquet nail
* Red lunulae
* Shell nail syndrome
* Splinter hemorrhage
* Spotted lunulae
* Staining of the nail plate
* Stippled nails
* Subungual hematoma
* Terry's nails
* Twenty-nail dystrophy

Hair|

| Hair loss/
Baldness|

* noncicatricial alopecia: Alopecia
* areata
* totalis
* universalis
* Ophiasis

* Androgenic alopecia (male-pattern baldness)
* Hypotrichosis
* Telogen effluvium
* Traction alopecia
* Lichen planopilaris
* Trichorrhexis nodosa
* Alopecia neoplastica
* Anagen effluvium
* Alopecia mucinosa

* cicatricial alopecia: Pseudopelade of Brocq
* Central centrifugal cicatricial alopecia
* Pressure alopecia
* Traumatic alopecia
* Tumor alopecia
* Hot comb alopecia
* Perifolliculitis capitis abscedens et suffodiens
* Graham-Little syndrome
* Folliculitis decalvans

* ungrouped: Triangular alopecia
* Frontal fibrosing alopecia
* Marie Unna hereditary hypotrichosis

|

Hypertrichosis|

* Hirsutism
* Acquired
* localised
* generalised
* patterned
* Congenital
* generalised
* localised
* X-linked
* Prepubertal

Acneiform
eruption|

| Acne|

* 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

|

Rosacea|

* Perioral dermatitis
* Granulomatous perioral dermatitis
* Phymatous rosacea
* Rhinophyma
* Blepharophyma
* Gnathophyma
* Metophyma
* Otophyma
* Papulopustular rosacea
* Lupoid rosacea
* Erythrotelangiectatic rosacea
* Glandular rosacea
* Gram-negative rosacea
* Steroid rosacea
* Ocular rosacea
* Persistent edema of rosacea
* Rosacea conglobata
* variants
* Periorificial dermatitis
* Pyoderma faciale

Ungrouped|

* Granulomatous facial dermatitis
* Idiopathic facial aseptic granuloma
* Periorbital dermatitis
* SAPHO syndrome

Follicular cysts|

* "Sebaceous cyst"
* Epidermoid cyst
* Trichilemmal cyst
* Steatocystoma
* simplex
* multiplex
* Milia

Inflammation|

* Folliculitis
* Folliculitis nares perforans
* Tufted folliculitis
* Pseudofolliculitis barbae

* Hidradenitis
* Hidradenitis suppurativa
* Recurrent palmoplantar hidradenitis
* Neutrophilic eccrine hidradenitis

Ungrouped|

* Acrokeratosis paraneoplastica of Bazex
* Acroosteolysis
* Bubble hair deformity
* Disseminate and recurrent infundibulofolliculitis
* Erosive pustular dermatitis of the scalp
* Erythromelanosis follicularis faciei et colli
* Hair casts
* Hair follicle nevus
* Intermittent hair–follicle dystrophy
* Keratosis pilaris atropicans
* Kinking hair
* Koenen's tumor
* Lichen planopilaris
* Lichen spinulosus
* Loose anagen syndrome
* Menkes kinky hair syndrome
* Monilethrix
* Parakeratosis pustulosa
* Pili (Pili annulati
* Pili bifurcati
* Pili multigemini
* Pili pseudoannulati
* Pili torti)
* Pityriasis amiantacea
* Plica neuropathica
* Poliosis
* Rubinstein–Taybi syndrome
* Setleis syndrome
* Traumatic anserine folliculosis
* Trichomegaly
* Trichomycosis axillaris
* Trichorrhexis (Trichorrhexis invaginata
* Trichorrhexis nodosa)
* Trichostasis spinulosa
* Uncombable hair syndrome
* Wooly hair nevus

Sweat
glands|

| Eccrine|

* Miliaria
* Colloid milium
* Miliaria crystalline
* Miliaria profunda
* Miliaria pustulosa
* Miliaria rubra
* Occlusion miliaria
* Postmiliarial hypohidrosis
* Granulosis rubra nasi
* Ross’ syndrome
* Anhidrosis
* Hyperhidrosis
* Generalized
* Gustatory
* Palmoplantar

|

Apocrine|

* Body odor
* Chromhidrosis
* Fox–Fordyce disease

Sebaceous|

* Sebaceous hyperplasia

* v
* t
* e

Diseases of the skin and appendages by morphology

Growths|

| Epidermal|

* Wart
* Callus
* Seborrheic keratosis
* Acrochordon
* Molluscum contagiosum
* Actinic keratosis
* Squamous-cell carcinoma
* Basal-cell carcinoma
* Merkel-cell carcinoma
* Nevus sebaceous
* Trichoepithelioma

|

Pigmented|

* 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

Rashes|

| With
epidermal
involvement|

| Eczematous|

* 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

|

Scaling|

* Psoriasis
* Tinea (Corporis
* Cruris
* Pedis
* Manuum
* Faciei)
* Pityriasis rosea
* Secondary syphilis
* Mycosis fungoides
* Systemic lupus erythematosus
* Pityriasis rubra pilaris
* Parapsoriasis
* Ichthyosis

Blistering|

* Herpes simplex
* Herpes zoster
* Varicella
* Bullous impetigo
* Acute contact dermatitis
* Pemphigus vulgaris
* Bullous pemphigoid
* Dermatitis herpetiformis
* Porphyria cutanea tarda
* Epidermolysis bullosa simplex

Papular|

* Scabies
* Insect bite reactions
* Lichen planus
* Miliaria
* Keratosis pilaris
* Lichen spinulosus
* Transient acantholytic dermatosis
* Lichen nitidus
* Pityriasis lichenoides et varioliformis acuta

Pustular|

* Acne vulgaris
* Acne rosacea
* Folliculitis
* Impetigo
* Candidiasis
* Gonococcemia
* Dermatophyte
* Coccidioidomycosis
* Subcorneal pustular dermatosis

Hypopigmented|

* Tinea versicolor
* Vitiligo
* Pityriasis alba
* Postinflammatory hyperpigmentation
* Tuberous sclerosis
* Idiopathic guttate hypomelanosis
* Leprosy
* Hypopigmented mycosis fungoides

Without
epidermal
involvement|

| Red|

| Blanchable
Erythema|

| Generalized|

* Drug eruptions
* Viral exanthems
* Toxic erythema
* Systemic lupus erythematosus

|

Localized|

* Cellulitis
* Abscess
* Boil
* Erythema nodosum
* Carcinoid syndrome
* Fixed drug eruption

Specialized|

* Urticaria
* Erythema (Multiforme
* Migrans
* Gyratum repens
* Annulare centrifugum
* Ab igne)

Nonblanchable
Purpura|

| Macular|

* Thrombocytopenic purpura
* Actinic/solar purpura

|

Papular|

* Disseminated intravascular coagulation
* Vasculitis

Indurated|

* Scleroderma/morphea
* Granuloma annulare
* Lichen sclerosis et atrophicus
* Necrobiosis lipoidica

Miscellaneous
disorders|

| Ulcers|

|

Hair|

* Telogen effluvium
* Androgenic alopecia
* Alopecia areata
* Systemic lupus erythematosus
* Tinea capitis
* Loose anagen syndrome
* Lichen planopilaris
* Folliculitis decalvans
* Acne keloidalis nuchae

Nail|

* Onychomycosis
* Psoriasis
* Paronychia
* Ingrown nail

Mucous
membrane|

* Aphthous stomatitis
* Oral candidiasis
* Lichen planus
* Leukoplakia
* Pemphigus vulgaris
* Mucous membrane pemphigoid
* Cicatricial pemphigoid
* Herpesvirus
* Coxsackievirus
* Syphilis
* Systemic histoplasmosis
* Squamous-cell carcinoma

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