A keloid is a raised growth of fibrous scar tissue that forms over an area of trauma to the skin and extends beyond the area of the original injury. Keloids generally form after a skin injury heals. For unknown reasons, some people produce an excess of dense, fibrous tissue at and around the site of injury. A keloid is abnormal because the scar extends above and beyond the site of the original injury. Normal scars stay confined to the site of injury. Keloids are thick, smooth areas of pink scar
tissue. The scar tissue is raised above the level of the surrounding skin. Some keloids are itchy or tender. Keloids can occur on any skin area. The most common locations for keloids vary according to race. In Caucasians, for example, keloids are most common on the face and arms. Blacks tend to develop keloids most often on the face and legs.
Keloids look like exaggerated scars. They are raised above the skin around them and sometimes they are domed. They can extend beyond the limits of the skin damage that caused the scar to come up in the first place. They are shiny and hairless; usually they feel hard and rubbery; and new ones are often red or purple, becoming browner and sometimes paler as they age. Most people with keloids have only one or two. However some people have many, especially if they have come up after acne or chickenpox scars.
The incidence of keloid scar formation in human beings is much greater in darker skinned individuals and African-Americans. There is approximately a 15 times greater incidence of keloid formation in African-Americans than in Caucasians. One of the most significant aspects of keloid formation is that of its relationship to trauma or injury of the skin. Accidental or surgical injury to the skin is a predisposing factor to keloid formation. On the other hand, many keloids will form without any significant relationship to trauma, injury or surgery to the skin. The site of development of keloids is also of importance. There are specific areas of the body that are much more prone to keloid formation. The chest and presternal areas are significantly at risk for keloid formation. Also the shoulders and deltoid regions are commonly affected by keloids. Skin tension is a factor. Clearly, increased skin tension such as occurs in the shoulder area is a predisposing factor. On the other hand, the central portion of the face in and around the nose and lips is less likely and uncommonly is noted to have keloids.
There is no truly effective treatment for keloids. They may be reduced in size through a corticosteroid injection or application of topical retinoids, or removed by freezing with liquid nitrogen (cryosurgery). However, new keloids often develop at the site of the treatment. Keloids can be reduced in size by applying a sheet of silicon gel over the growth. Keloids that are disfiguring because of location and color may be improved through pulse dye laser treatment.
Simple surgical excision and closure can cause a re-occurrence of the problem in approximately 50% of individuals. Radiation therapy to the keloid healing site has also been met with some success, particularly when a certain amount of radiation (1,500 to 2,000 rads) are given to the healing site in the postoperative period. Decreasing the skin tension can also benefit the keloids. Some physicians recommend skin grafting to the healing site so as to decrease the tension to the area and promote normal healing and lessen the chance for keloid formation.
Pharmacological management has been also utilized for keloid treatment. This has been met with some success. The benefits of pharmacological management is that surgery is not required. Radiation and other modalities can be invasive. Intralesional injection with Triamcinolone tends to decrease the tendency for keloid and hypertrophic scar formation.
Triamcinolone injection does carry some risk, including an increased tendency for depigmentation, telangiectasias, and associated dermal and skin atrophy. Other treatment modalities have included Retin 0.5% (Retin A which has been shown to somewhat decrease keloid size). Additionally, zinc oxide and antineoplastic agents such as Nitrogen mustard, Tetroquinone, and Thiotepa were utilized with some success.
C02 laser treatment to keloids has also been utilized and studied. There has been some improvement in reduction of the keloid formation with the C02 laser, however it is not noted in the majority of individuals. Other treatments have included non-antibiotic moisturizing ointments. However, it should be understood that there is no clear answer for keloid and hypertrophic scar formation. Some individuals simply have the tendency to develop keloids and despite surgical laser, chemotherapy, radiation therapy, or pharmaceutical agents, the keloids can persist. Therefore, it is imperative that an individual understands the potential limitations of medical and surgical treatment for keloids and keep an open mind about overall potential success.