Keloids


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Keloids

 

Definition

Keloids are overgrowths of fibrous tissue or scars that can occur after an injury to the skin. These heavy scars are also called cheloid or hypertrophic scars. In individuals prone to keloids, even minor traumas to the skin, such as ear piercing, can cause keloids. The word "keloid" itself comes from the Greek word for a crab's claw; it was first used by a French physician to describe the way that keloids grow sideways into normal skin.

Description

Keloids can occur anywhere on the body, but they are most common on the earlobes, upper back, shoulders, and chest. The pattern of distribution of keloids differs according to race, with facial keloids more common in Caucasians and relatively uncommon in Asians. African Americans are more likely to develop keloids on the legs or feet than either Asians or Caucasians. In general, keloids consist of hard, raised scars that may be slightly pink or whitish. These may itch and be painful, and some keloids can grow to be quite large.

Causes and symptoms

Although the cause of keloids is unknown, it is thought that they are due to the body's failure to turn off the healing process needed to repair skin. When this occurs, extra collagen forms at the site of the scar, and keeps forming because it is not shut off. This results in keloid formation.
Keloids occur most frequently in individuals of African-American descent and in those with darker skin. They are more common in Polynesians and Chinese than in people from India or Malaysia. Caucasians are the least frequently affected by keloids. Other risk factors include a family history of keloids, surgery, acne, burns, ear piercing, vaccinations, or even insect bites. Spontaneous keloids have been reported occasionally in siblings. In addition, women and young people under the age of 30 are more prone to develop them. Keloids are infrequent among the elderly.
Although the association of keloids with darker skin pigmentation suggests a genetic linkage of some sort, no specific genes have been identified in connection with keloids as of the early 2000s.
Initially, keloids will begin as a small lump where the skin has been injured. This lump grows and can eventually become very large and cosmetically unacceptable.

Diagnosis

A dermatologist can usually make the diagnosis of a keloid based on looking at the scar. In some cases, however, a biopsy may be necessary to rule out other types of skin lesions, such as tumors.

Treatment

The treatment of choice for keloids is usually an injection of corticosteroid drugs such as cortisone directly into the lesion. These injections cause the keloid to become atrophic, or thinner, and are repeated every three to four weeks until the keloid has been resolved to the individual's satisfaction. Other therapies include laser treatment or radiation therapy, and topical treatments are undergoing study.
Surgery is often used in combination with corticosteroid injections. The injections are given for several weeks, and then the keloid is surgically removed. The injections are then continued for several weeks. Surgical removal of the keloid may also be used in conjunction with radiation therapy, which delivers small amounts of radiation to the affected area.
Another surgical option is cryosurgery, in which liquid nitrogen is used to freeze the tissues in the keloid. The treatment may need to be repeated to remove as much of the keloid as possible; however, cryosurgery prevents keloids from recurring in about 70% of patients.
Newer approaches include silastic gel sheeting, which makes use of pressure to flatten the keloid. The gel is applied and kept securely in place with tape, cloth, or an Ace bandage. The dressing is to be changed every seven to 10 days for as long as 12 months.
Finally, researchers are now studying a type of tape that has been soaked with steroids, which are released slowly into the keloid, causing it to thin over time.
Newer treatments include injections of interferon directly into the keloids, and local application of 5% imiquimod cream, which induces the skin where it is applied to produce interferon. The imiquimod cream is reported to significantly lower the risk of keloid recurrence.

Prognosis

Although keloids are unsightly, they are not life-threatening. Keloids do not have a tendency to develop into malignancies, but they can become cosmetically unacceptable. Keloids can gradually lessen after treatment, but many recur. And just as they can occur spontaneously, they can also resolve spontaneously.

Prevention

Preventive measures include avoiding any trauma to the skin, and compression pressure dressing for high-risk patients who have suffered burns to their skin. Patients with a tendency to form keloids should avoid any sort of elective surgery. Individuals who are prone to develop keloids or who have a history of keloids should immediately care for any cuts or abrasions they may sustain.
To lower the risk of keloids, surgeons are advised to close incisions with as little tension on the sutures as possible, and to use buried sutures whenever possible.

Key terms

Atrophy — A wasting away of, becoming thinner, less strong.
Corticosteroids — Any of several steroid medications used to suppress inflammation, allergic, or immune responses of the body.
Cryosurgery — The use of extreme cold to kill or remove tissue.

Resources

Books

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Benign Tumors." Section 10, Chapter 125 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Periodicals

Berman, Brian, MD, PhD, and Sonia Kapoor, MBBS. "Keloid and Hypertrophic Scar." eMedicine November 30, 2001. http://www.emedicine.com/derm/topic205.htm.
Dinh, Q., M. Veness, and S. Richards. "Role of Adjuvant Radiotherapy in Recurrent Earlobe Keloids." Australasian Journal of Dermatology 45 (August 2004): 162-166.
Food and Drug Administration (FDA). "General and Plastic Surgery Devices; Classification of Silicone Sheeting. Final Rule." Federal Register 69 (August 9, 2004): 48146-48148.
Mandal, A., D. Imran, and G. S. Rao. "Spontaneous Keloids in Siblings." Irish Medical Journal 97 (September 2004): 250-251.

Organizations

American Academy of Dermatology. 930 N. Meacham Road, PO Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. Fax: (847) 330-0050. http://www.aad.org.
United States Food and Drug Administration (FDA). 5600 Fishers Lane, Rockville, MD 20857-0001. (888) INFO-FDA. http://www.fda.gov.

Other

http://www.skinsite.com.
"Keloids." Black Women's Health. 〈http://www.black-womenshealth.com/Keloids.htm〉.
References in periodicals archive ?
One way of looking at a tattoo is that it's ink under the skin and that alone makes it a risk in getting blood-borne diseases like HIV and hepatitis, skin infections, and of course, keloids.
Addition of external Transforming Growth Factor Beta 1 stimulates fibroblasts, thereby increasing production of collagen, and formation of keloids (Chen et al.
Comparative results in treatment of keloids with intralesional 5-FU/Kenalog, 5-FU/verapamil, enalapril alone, verapamil alone, and laser: a case report and review of the literature.
De Bearman and Gourgerot have first described the treatment of keloids using superficial X-ray irradiation in 1906, other detailed reports on using X-ray as a treatment method for keloids surfaced around 1920 and 1933.
4 Till date, keloids pose a challenge to the dermatologists due to their ability to recur in spite of adequate treatment and variable response to different therapies available.
It is formed in greater amounts in keloids and keloid fibroblasts react to lesser amounts of TGFB1 than non-keloid fibroblasts.
About 250,000 US patients undergo surgical treatment annually for keloids, which are firm, overgrown scars, and for other types of excessive scarring, Iyer says.
The report reviews key players involved in the therapeutics development for Keloids and enlists all their major and minor projects
Interestingly, some patients develop keloids at their ear cartilage piercing sites, whereas the common sites for keloid formation like earlobe, back, front of chest and shoulders are spared.
This study was focus to provide a concern of efficacy for clinical scars management of keloids and hypertrophic scars formation in future.
Excessive production of CTGF is considered a major cause of abnormal scarring, such as hypertrophic scars and keloids.
The main features differentiating keloid scars from hypertrophic scars are that keloid scars enlarge and extend beyond the original injury site, there is no spontaneous regression and following excision there is a high recurrence rate.