keloid

Image:Keloid.jpg

Keloids expand in claw-like growths over normal skin.{{cite journal | vauthors = Babu M, Meenakshi J, Jayaraman V, Ramakrishnan |date = July 2005 |title=Keloids and hypertrophic scars: A review |journal=Indian Journal of Plastic Surgery |volume=38 |issue=2 |pages=175–9 |doi=10.4103/0970-0358.19796|doi-access= free}} They can hurt with a needle-like pain or to itch, the degree of sensation varying from person to person.{{cn|date=July 2022}}

Keloids typically form within scar tissue. Collagen, used in wound repair, tends to overgrow in this area, sometimes producing a lump many times larger than that of the original scar. They can also range in color from pink to red.{{Cite web | vauthors = Cole GW | veditors = Stöppler MC | date = 27 July 2022 |title = Keloid Scar: Find Causes, Symptoms, and Removal|url = http://www.medicinenet.com/keloid/article.htm|website = MedicineNet|access-date = 2016-02-11}} Although they usually occur at the site of an injury, keloids can also arise spontaneously. They can occur at the site of a piercing and even from something as simple as a pimple or scratch. They can occur as a result of severe acne or chickenpox scarring, infection at a wound site, repeated trauma to an area, excessive skin tension during wound closure or a foreign body in a wound. Keloids can sometimes be sensitive to chlorine.{{Citation Needed|date=January 2024}} If a keloid appears when someone is still growing, the keloid can continue to grow as well.{{cn|date=July 2022}}

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File:Keloid_Papule.JPG |Small size keloid papules

File:Keloid-Nodular, Keloid Tumor.JPG |Keloid nodules (1–2 cm in diameter) and a keloid tumor >2 cm in diameter

File:Liner_Keloids.JPG |Two linear keloids

File:Flat_keloid.JPG |Patch of flat keloid

File:Butterfly_Keloid.JPG |Butterfly type keloid

File:Guttate_Keloid.JPG |Guttate keloid

File:Keloid-Hyperinflammatory , Chest Wall Keloid, Butterfly Keloid.JPG |Hyper-inflammatory keloid of the chest wall

File:Superficially_Spreading_Keloid.jpg|Superficially spreading keloid

File:Pedunculated_Earlobe_Keloid.jpg |Pedunculated keloid that grows with a stalk, much like a mushroom

File:Earlobe_Keloid,_Bulky.JPG |Bulky keloid

File:Massive_Keloids.jpg |Large keloids

File:Keloid_Scalp,_Occipotal_Keloid.JPG|Scalp keloid in occipital area

File:Earlobe_Keloid_2.JPG|Earlobe keloid

File:Keloid-Earlobe_Massive.JPG|Large earlobe keloid forming after repeated surgeries

File:Posterior_Auricular_Keloid.JPG|Posterior auricular keloid triggered by otoplasty surgery

File:Keloid-Face_Nodular,_Facial_Keloid.JPG|Facial nodular keloids in African American male

File:Keloid-Neck,_Bulky_Keloid.JPG|Bulky keloid of the neck

File:Chest_Wall_Keloid.JPG|Inflammatory keloid of the chest wall, worsened with surgery

File:Upper_Arm_Keloid.JPG|Flat, superficially spreading keloid in the upper arm area

File:Keloid_Disorder_-_Umbilical_Keloid,_Keloid_on_belly_button.jpg|Pedunculated umblical keloid

File:Pubic_keloids.JPG|Multi-nodular conglomerate of the pubic area, worsened with surgery.

File:Sole_of_Foot_Keloid.JPG|Keloid in the sole in a patient with large keloids elsewhere

File:Umbilical_Keloid_from_Piercing.JPG| Well-healed midline scar of surgery, with keloid forming in the navel area following piercing

File:Tattoo_keloid.JPG|Keloid formation triggered by tattooing

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Keloids can develop in any place where skin trauma has occurred. They can be the result of pimples, insect bites, scratching, burns, or other skin injuries. Keloid scars can develop after surgery. They are more common in some sites, such as the central chest (from a sternotomy), the back and shoulders (usually resulting from acne), and the ear lobes (from ear piercings). They can also occur on body piercings. The most common spots are the earlobes, arms, pelvic region, and over the collarbone.{{cn|date=July 2022}}

Most skin injury types can contribute to scarring. This includes burns, acne scars, chickenpox scars, ear piercing, scratches, surgical incisions, and vaccination sites.

According to the US National Center for Biotechnology Information, keloid scarring is common in young people between the ages of 10 and 20. Studies have shown that those with darker complexions are at a higher risk of keloid scarring as a result of skin trauma. They occur in 15–20% of individuals with sub-Saharan African, Asian, or Latino ancestry, significantly less in those of a Caucasian background. Although it was previously believed that people with albinism did not get keloids,{{cite journal | vauthors = Andrews JP, Marttala J, Macarak E, Rosenbloom J, Uitto J | title = Keloids: The paradigm of skin fibrosis - Pathomechanisms and treatment | journal = Matrix Biology | volume = 51 | pages = 37–46 | date = April 2016 | pmid = 26844756 | pmc = 4842154 | doi = 10.1016/j.matbio.2016.01.013 }} a recent report described the incidence of keloids in Africans with albinism.{{cite journal | vauthors = Kiprono SK, Chaula BM, Masenga JE, Muchunu JW, Mavura DR, Moehrle M | title = Epidemiology of keloids in normally pigmented Africans and African people with albinism: population-based cross-sectional survey | journal = The British Journal of Dermatology | volume = 173 | issue = 3 | pages = 852–854 | date = September 2015 | pmid = 25833201 | doi = 10.1111/bjd.13826 | s2cid = 20641975 }} Keloids tend to have a genetic component, which means one is more likely to have keloids if one or both of their parents have them. However, no single gene has yet been identified which is a causing factor in keloid scarring but several susceptibility loci have been discovered, most notably in Chromosome 15.{{cite web | title = Keloids | date = 5 October 2010 | work = PubMed Health | publisher = U.S. National Library of Medicine | url = https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001852/ | archive-url = https://web.archive.org/web/20110216153149/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001852/ | archive-date = 16 February 2011 }}

File:The Surgical history of the naval war between Japan and China - during 1894-95; translated from the original Japanese report (1900) (14595050100).jpg. People of Asian descent are among the groups more likely to develop keloid scars.]]

People who have ancestry from Sub-Saharan Africa, Asia, or Latin America are more likely to develop a keloid. Among ethnic Chinese in Asia, the keloid is the most common skin condition. In the United States, keloids are more common in African Americans and Hispanic Americans than European Americans. Those who have a family history of keloids are also susceptible since about 1/3 of people who get keloids have a first-degree blood relative (mother, father, sister, brother, or child) who also gets keloids. This family trait is most common in people of African and/or Asian descent.

The development of keloids among twins also lends credibility to the existence of a genetic susceptibility to develop keloids. Marneros et al. (1) reported four sets of identical twins with keloids; Ramakrishnan et al.{{cite journal | vauthors = Ramakrishnan KM, Thomas KP, Sundararajan CR | title = Study of 1,000 patients with keloids in South India | journal = Plastic and Reconstructive Surgery | volume = 53 | issue = 3 | pages = 276–280 | date = March 1974 | pmid = 4813760 | doi = 10.1097/00006534-197403000-00004 }} also described a pair of twins who developed keloids at the same time after vaccination. Case series have reported clinically severe forms of keloids in individuals with positive family history and black African ethnic origin.

File:Keloid -1.jpg

Histologically, keloids are fibrotic tumors characterized by a collection of atypical fibroblasts with excessive deposition of extracellular matrix components, especially collagen, fibronectin, elastin, and proteoglycans. Generally, they contain relatively acellular centers and thick, abundant collagen bundles that form nodules in the deep dermal portion of the lesion. Keloids present a therapeutic challenge that must be addressed, as these lesions can cause significant pain, {{lang|la|pruritus}} (itching), and physical disfigurement. They may not improve in appearance over time and can limit mobility if located over a joint.{{Cite web |date=2019-04-01 |title=Keloids |url=https://www.health.harvard.edu/a_to_z/keloids-a-to-z |access-date=2024-08-12 |website=Harvard Health |language=en}}

Keloids affect all sexes equally, although the incidence in young female patients has been reported to be higher than in young males, probably reflecting the greater frequency of earlobe piercing among women. The frequency of occurrence is 15 times higher in highly pigmented people. People of African descent have an increased risk of keloid occurrences.{{EMedicine|article|1298013|Wound Healing, Keloids}}

Prevention of keloid scars in patients with a known predisposition to them includes preventing unnecessary trauma or surgery (such as ear piercing and elective mole removal) whenever possible. Any skin problems in predisposed individuals (e.g., acne, infections) should be treated as early as possible to minimize areas of inflammation.

Treatments (both preventive and therapeutic) available are pressure therapy, silicone gel sheeting, intra-lesional triamcinolone acetonide (TAC), cryosurgery (freezing), radiation, pulsed dye laser (PDL), interferon (IFN), fluorouracil (5-FU) and surgical excision as well as a multitude of extracts and topical agents.{{cite journal | vauthors = Gauglitz GG, Korting HC, Pavicic T, Ruzicka T, Jeschke MG | title = Hypertrophic scarring and keloids: pathomechanisms and current and emerging treatment strategies | journal = Molecular Medicine | volume = 17 | issue = 1–2 | pages = 113–125 | year = 2011 | pmid = 20927486 | pmc = 3022978 | doi = 10.2119/molmed.2009.00153 }} Appropriate treatment of a keloid scar is age-dependent: radiotherapy, anti-metabolites, and corticosteroids would not be recommended to be used in children, to avoid harmful side effects, like growth abnormalities.{{cite journal | vauthors = Arno AI, Gauglitz GG, Barret JP, Jeschke MG | title = Up-to-date approach to manage keloids and hypertrophic scars: a useful guide | journal = Burns | volume = 40 | issue = 7 | pages = 1255–1266 | date = November 2014 | pmid = 24767715 | pmc = 4186912 | doi = 10.1016/j.burns.2014.02.011 }}

In adults, corticosteroids combined with 5-FU and PDL in triple therapy enhance results and diminish side effects.

Cryotherapy (or cryosurgery) refers to the application of extreme cold to treat keloids. This treatment method is easy to perform, effective, safe, and has the least chance of recurrence.{{cite journal | vauthors = Zouboulis CC, Blume U, Büttner P, Orfanos CE | title = Outcomes of cryosurgery in keloids and hypertrophic scars. A prospective consecutive trial of case series | journal = Archives of Dermatology | volume = 129 | issue = 9 | pages = 1146–1151 | date = September 1993 | pmid = 8363398 | doi = 10.1001/archderm.1993.01680300074011 }}{{Cite web|date=2016-11-07|title=Keloid Research Foundation|url=http://www.keloidresearchfoundation.org/treatment-options.php|access-date=2020-07-13|archive-url=https://web.archive.org/web/20161107173532/http://www.keloidresearchfoundation.org/treatment-options.php|archive-date=2016-11-07}}

Surgical excision is currently still the most common treatment for a significant number of keloid lesions. However, when used as the solitary form of treatment, there is a large recurrence rate of between 70 and 100%. It has also been known to cause a larger lesion formation on recurrence. While not always successful alone, surgical excision when combined with other therapies dramatically decreases the recurrence rate. Examples of these therapies include but are not limited to radiation therapy, pressure therapy, and laser ablation. Pressure therapy following surgical excision has shown promising results, especially in keloids of the ear and earlobe. The mechanism of how exactly pressure therapy works is unknown at present, but many patients with keloid scars and lesions have benefited from it.

Intralesional injection with a corticosteroid such as triamcinolone acetonide does appear to aid in the reduction of fibroblast activity, inflammation and pruritus.{{cite journal | vauthors = Griffith BH | title = The treatment of keloids with triamcinolone acetonide | journal = Plastic and Reconstructive Surgery | volume = 38 | issue = 3 | pages = 202–208 | date = September 1966 | pmid = 5919603 | doi = 10.1097/00006534-196609000-00004 }}

Tea tree oil, salt, or other topical oil does not affect keloid lesions.{{cite web|url=https://www.txid.org/?page_id=4043|title=Keloid Treatment|access-date=22 November 2018 | work = Texas Institute of Dermatology }}

A 2022 systematic review included multiple studies on laser therapy for treating keloid scars. There was not enough evidence for the review authors to determine if laser therapy was more effective than other treatments. They were also unable to conclude whether laser therapy leads to more harm than benefits compared with no treatment or different kinds of treatment.{{cite journal | vauthors = Leszczynski R, da Silva CA, Pinto AC, Kuczynski U, da Silva EM | title = Laser therapy for treating hypertrophic and keloid scars | journal = The Cochrane Database of Systematic Reviews | volume = 2022 | issue = 9 | pages = CD011642 | date = September 2022 | pmid = 36161591 | pmc = 9511989 | doi = 10.1002/14651858.CD011642.pub2 | collaboration = Cochrane Wounds Group }}

Another 2022 systematic review compared silicone gel sheeting with no treatment, treatment with non-silicone gel sheeting, and treatment with intralesional injections of triamcinolone acetonide. The authors only found two small studies (36 participants in total) that compared these treatment options, so they were unable to determine which (if any) was more effective.{{cite journal | vauthors = Tian F, Jiang Q, Chen J, Liu Z | title = Silicone gel sheeting for treating keloid scars | journal = The Cochrane Database of Systematic Reviews | volume = 1 | issue = 1 | pages = CD013878 | date = January 2023 | pmid = 36594476 | pmc = 9808890 | doi = 10.1002/14651858.CD013878.pub2 | collaboration = Cochrane Wounds Group }}

File:Medical aspect, Hiroshima, Japan, 1946-03-23, 342-USAF-11034.ogv

People of any age can develop a keloid. Children under 10 are less likely to develop keloids, even from ear piercing. Keloids may also develop from pseudofolliculitis barbae; continued shaving when one has razor bumps will irritate the bumps, infection, and over time, keloids will form. Persons with razor bumps are advised to stop shaving for the skin to repair itself before undertaking any form of hair removal. The tendency to form keloids is speculated to be hereditary.{{cite journal | vauthors = Halim AS, Emami A, Salahshourifar I, Kannan TP | title = Keloid scarring: understanding the genetic basis, advances, and prospects | journal = Archives of Plastic Surgery | volume = 39 | issue = 3 | pages = 184–189 | date = May 2012 | pmid = 22783524 | pmc = 3385329 | doi = 10.5999/aps.2012.39.3.184 }} Keloids can tend to appear to grow over time without even piercing the skin, almost acting out a slow tumorous growth; the reason for this tendency is unknown.

Extensive burns, either thermal or radiological, can lead to unusually large keloids; these are especially common in firebombing casualties and were a signature effect of the atomic bombings of Hiroshima and Nagasaki.

The true incidence and prevalence of keloid in the United States are not known. Indeed, there has never been a population study to assess the epidemiology of this disorder. In his 2001 publication, Marneros{{cite journal | vauthors = Marneros AG, Norris JE, Olsen BR, Reichenberger E | title = Clinical genetics of familial keloids | journal = Archives of Dermatology | volume = 137 | issue = 11 | pages = 1429–1434 | date = November 2001 | pmid = 11708945 | doi = 10.1001/archderm.137.11.1429 | doi-access = }} stated that “reported incidence of keloids in the general population ranges from a high of 16% among the adults in the Democratic Republic of the Congo to a low of 0.09% in England,” quoting from Bloom's 1956 publication on heredity of keloids.{{cite journal | vauthors = Bloom D | title = Heredity of keloids; review of the literature and report of a family with multiple keloids in five generations | journal = New York State Journal of Medicine | volume = 56 | issue = 4 | pages = 511–519 | date = February 1956 | pmid = 13288798 }} Clinical observations show that the disorder is more common among sub-Saharan Africans, African Americans and Asians, with unreliable and very wide estimated prevalence rates ranging from 4.5 to 16%.{{cite journal | vauthors = Froelich K, Staudenmaier R, Kleinsasser N, Hagen R | title = Therapy of auricular keloids: review of different treatment modalities and proposal for a therapeutic algorithm | journal = European Archives of Oto-Rhino-Laryngology | volume = 264 | issue = 12 | pages = 1497–1508 | date = December 2007 | pmid = 17628822 | doi = 10.1007/s00405-007-0383-0 | s2cid = 25168874 }}{{cite journal | vauthors = Gauglitz GG, Korting HC, Pavicic T, Ruzicka T, Jeschke MG | title = Hypertrophic scarring and keloids: pathomechanisms and current and emerging treatment strategies | journal = Molecular Medicine | volume = 17 | issue = 1–2 | pages = 113–125 | year = 2011 | pmid = 20927486 | pmc = 3022978 | doi = 10.2119/molmed.2009.00153 }}

File:Scourged back by McPherson & Oliver, 1863, retouched.jpg

Keloids were described by Egyptian surgeons around 1700 BCE, recorded in the Smith papyrus, regarding surgical techniques.{{Citation needed|date=March 2010}} Baron Jean-Louis Alibert (1768–1837) identified the keloid as an entity in 1806.{{Citation needed|date=March 2010}} He called them {{lang|fr|cancroïde}}, later changing the name to {{lang|fr|chéloïde}} to avoid confusion with cancer. The word is derived from the Ancient Greek {{wikt-lang|grc|χηλή}}, {{transliteration|grc|chele}}, meaning "crab pincers", and the suffix -oid, meaning "like". In the 19th century it was known as the "Keloid of Alibert" as opposed to "Addison’s keloid" (Morphea).{{cite web |url=http://www.whonamedit.com/synd.cfm/94.html |title=Alibert's disease I |author= |website=Whonamedit?}}

The famous American Civil War-era photograph "Whipped Peter" depicts an escaped former slave with extensive keloid scarring as a result of numerous brutal beatings from his former overseer.

Intralesional corticosteroid injections were introduced as a treatment in the mid-1960s as a method to attenuate scarring.{{cite journal | vauthors = Gauglitz GG, Korting HC, Pavicic T, Ruzicka T, Jeschke MG | title = Hypertrophic scarring and keloids: pathomechanisms and current and emerging treatment strategies | journal = Molecular Medicine | volume = 17 | issue = 1–2 | pages = 113–125 | date = 2010-10-05 | pmid = 20927486 | pmc = 3022978 | doi = 10.2119/molmed.2009.00153 | publisher = Springer Science and Business Media LLC }}

Pressure therapy has been used for the prophylaxis and treatment of keloids since the 1970s.

Topical silicone gel sheeting was introduced as a treatment in the early 1980s.

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{{commons category|Keloid}}

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• {{cite book | vauthors = Roßmann N |title=Beitrag zur Pathogenese des Keloids und seine Beeinflussbarkeit durch Steroidinjektionen |year=2005 |type=PhD Thesis |oclc=179740918 |url=http://d-nb.info/974328308/34 |language=de |trans-title=Contribution to the pathogenesis of the keloid and its influence by steroid injections }}
• {{cite journal | vauthors = Ogawa R, Mitsuhashi K, Hyakusoku H, Miyashita T | title = Postoperative electron-beam irradiation therapy for keloids and hypertrophic scars: retrospective study of 147 cases followed for more than 18 months | journal = Plastic and Reconstructive Surgery | volume = 111 | issue = 2 | pages = 547–53; discussion 554–5 | date = February 2003 | pmid = 12560675 | doi = 10.1097/01.PRS.0000040466.55214.35 | s2cid = 8411788 }}
• {{cite journal | vauthors = Okada E, Maruyama Y | title = Are keloids and hypertrophic scars caused by fungal infection? | journal = Plastic and Reconstructive Surgery | volume = 120 | issue = 3 | pages = 814–815 | date = September 2007 | pmid = 17700144 | doi = 10.1097/01.prs.0000278813.23244.3f | doi-access = free }}

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{{Medical resources

| DiseasesDB =

| ICD10 = {{ICD10|L|91|0|l|80}}

| ICD9 = {{ICD9|701.4}}

| ICDO =

| OMIM =

| MedlinePlus = 000849

| eMedicineSubj = article

| eMedicineTopic = 1057599

| eMedicine_mult = {{eMedicine2|article|1298013}}

| MeshID = D007627

}}

{{Diseases of the skin and appendages by morphology}}

{{Localized connective tissue diseases}}{{Female genital mutilation}}

Category:Dermal and subcutaneous growths

Category:Radiation health effects

Category:Scarring