Keloid

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Keloid
Bulky keloid forming at the site of abdominal surgery
Pronunciation
SpecialtyDermatology
Usual onsetscar formation

Keloid, also known as keloid disorder and keloidal scar,

benign and not contagious, but sometimes accompanied by severe itchiness, pain,[2] and changes in texture. In severe cases, it can affect movement of skin. In the United States keloid scars are seen 15 times more frequently in people of sub-Saharan African descent than in people of European descent.[citation needed] There is a higher tendency to develop a keloid among those with a family history of keloids and people between the ages of 10 and 30 years.[citation needed
]

Keloids should not be confused with hypertrophic scars, which are raised scars that do not grow beyond the boundaries of the original wound.

Signs and symptoms

Postoperative keloid on the wrist

Keloids expand in claw-like growths over normal skin.[3] They have the capability to hurt with a needle-like pain or to itch, the degree of sensation varying from person to person.[citation needed]

Keloids form within

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] If a keloid appears when someone is still growing, the keloid can continue to grow as well.[citation needed
]

Images
  • Small size keloid papules
    Small size keloid papules
  • Keloid nodules (1–2 cm in diameter) and a keloid tumor >2 cm in diameter
    Keloid nodules (1–2 cm in diameter) and a keloid tumor >2 cm in diameter
  • Two linear keloids
    Two linear keloids
  • Patch of flat keloid
    Patch of flat keloid
  • Butterfly type keloid
    Butterfly type keloid
  • Guttate keloid
    Guttate keloid
  • Hyper-inflammatory keloid of the chest wall
    Hyper-inflammatory keloid of the chest wall
  • Superficially spreading keloid
    Superficially spreading keloid
  • Pedunculated keloid that grows with a stalk, much like a mushroom
    Pedunculated keloid that grows with a stalk, much like a mushroom
  • Bulky keloid
    Bulky keloid
  • Large keloids
    Large keloids
  • Scalp keloid in occipital area
    Scalp keloid in occipital area
  • Earlobe keloid
    Earlobe keloid
  • Large earlobe keloid forming after repeated surgeries
    Large earlobe keloid forming after repeated surgeries
  • Posterior auricular keloid triggered by otoplasty surgery
    Posterior auricular keloid triggered by otoplasty surgery
  • Facial nodular keloids in African American male
    Facial nodular keloids in African American male
  • Bulky keloid of the neck
    Bulky keloid of the neck
  • Inflammatory keloid of the chest wall, worsened with surgery
    Inflammatory keloid of the chest wall, worsened with surgery
  • Flat, superficially spreading keloid in upper arm area
    Flat, superficially spreading keloid in upper arm area
  • Pedunculated umblical keloid
    Pedunculated umblical keloid
  • Multi-nodular conglomerate of pubic area, worsened with surgery.
    Multi-nodular conglomerate of pubic area, worsened with surgery.
  • Keloid in the sole of foot in a patient with large keloids elsewhere
    Keloid in the sole of foot in a patient with large keloids elsewhere
  • Well healed midline scar of surgery, with keloid forming in the navel area following piercing
    Well healed midline scar of surgery, with keloid forming in the navel area following piercing
  • Keloid formation triggered by tattooing
    Keloid formation triggered by tattooing

Location

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 injury. 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 earlobes, arms, pelvic region, and over the collar bone.[citation needed
]

Cause

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,[5] a recent report described the incidence of keloids in Africans with albinism.[6] Keloids tend to have a genetic component, which means one is more likely to have keloids if one or both of their parents has 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.[5][7]

Genetics

Japanese sailor with keloid scarring during the First Sino-Japanese War. 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.

Development of keloids among twins also lends credibility to existence of a genetic susceptibility to develop keloids. Marneros et al. (1) reported four sets of identical twins with keloids; Ramakrishnan et al.[8] 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 a positive family history and black African ethnic origin.

Pathology

Micrograph of keloid. Thick, hyalinised collagen fibres are characteristic of this aberrant healing process. H&E stain.

pruritus (itching), and physical disfigurement. They may not improve in appearance over time and can limit mobility if located over a joint.[citation needed
]

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 increased risk of keloid occurrences.[9]

Treatments

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,

pulsed dye laser), interferon (IFN), fluorouracil (5-FU) and surgical excision as well as a multitude of extracts and topical agents.[10] Appropriate treatment of a keloid scar is age-dependent: radiotherapy, anti-metabolites and corticosteroids would not be recommended to be used in children, in order to avoid harmful side effects, like growth abnormalities.[11]

In adults, corticosteroids combined with 5-FU and PDL in a triple therapy, enhance results and diminish side effects.[11]

Cryotherapy (or cryosurgery) refers to the application of extreme cold to treat keloids. This treatment method is easy to perform, effective and safe and has the least chance of recurrence.[12][13]

Surgical excision is currently still the most common treatment for a significant amount 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.[5]

Intralesional injection with a corticosteroid such as

pruritus.[14]

Tea tree oil, salt or other topical oil has no effect on keloid lesions.[15]

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 if laser therapy leads to more harm than benefits compared with no treatment or different kinds of treatment.[16]

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 were unable to determine which (if any) was more effective.[17]

Epidemiology

Hiroshima atomic bombing survivors showing numerous burn scars, including keloids

Persons 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 cause irritation to the bumps, infection, and over time keloids will form. Persons with razor bumps are advised to stop shaving in order for the skin to repair itself before undertaking any form of hair removal. The tendency to form keloids is speculated to be hereditary.[18] 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.

True incidence and prevalence of keloid in United States is not known. Indeed, there has never been a population study to assess the epidemiology of this disorder. In his 2001 publication, Marneros[19] 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.[20] 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%.[21][22]

History

Gordon or “Whipped Peter”, enslaved African American man displaying severe keloid scars

Keloids were described by Egyptian surgeons around 1700 

Baron Jean-Louis Alibert (1768–1837) identified the keloid as an entity in 1806.[citation needed] He called them cancroïde, later changing the name to chéloïde to avoid confusion with cancer. The word is derived from the Ancient Greek χηλή, 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).[23]

The famous

"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 was introduced as a treatment in mid-1960s as a method to attenuate scarring.[24]

Pressure therapy has been used for prophylaxis and treatment of keloids since the 1970s.[24]

Topical silicone gel sheeting was introduced as a treatment in the early 1980s.[24]

References

  1. .
  2. .
  3. .
  4. ^ Cole GW (27 July 2022). Stöppler MC (ed.). "Keloid Scar: Find Causes, Symptoms, and Removal". MedicineNet. Retrieved 2016-02-11.
  5. ^
    PMID 26844756
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  6. .
  7. ^ "Keloids". PubMed Health. U.S. National Library of Medicine. 5 October 2010. Archived from the original on 16 February 2011.
  8. PMID 4813760
    .
  9. ^ Wound Healing, Keloids at eMedicine
  10. PMID 20927486
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  11. ^ .
  12. .
  13. ^ "Keloid Research Foundation". 2016-11-07. Archived from the original on 2016-11-07. Retrieved 2020-07-13.
  14. PMID 5919603
    .
  15. ^ "Keloid Treatment". Texas Institute of Dermatology. Retrieved 22 November 2018.
  16. PMID 36161591
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  17. .
  18. .
  19. .
  20. .
  21. .
  22. .
  23. ^ "Alibert's disease I". Whonamedit?.
  24. ^
    PMID 20927486
    .

Further reading

External links

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