Although multiple management options are available for the treatment of keloids, they can be expensive and recurrence rates remain high. Therefore, prevention is paramount. Patients with a family history of keloids should avoid ear piercing, and those with a personal history should avoid elective surgical procedures, including LASIK surgery and CO2 laser resurfacing. Keloid development from dermatologic conditions, such as acne vulgaris, folliculitis, and varicella infection, should be a strong concern in high-risk individuals and should therefore be treated aggressively. Although small needlesticks are not associated with great risk for keloid formation, they have been known to occur following bacille Calmette-Gu&$233;rin vaccination.
Intralesional steroids are the most effective and widely used treatment for keloids. Intralesional triamcinolone acetonide, a potent anti-inflammatory fluoridated hydrocortisone, is often used as first-line therapy for keloids. The preferred method of delivery is intralesional injection. One study reported that intralesional injection of triamcinolone acetonide led to symptomatic improvement in 72% of patients and complete flattening in 64% of lesions. However, the long-term cure rates remain equivocal. One study found a 5-year recurrence rate of 50% when triamcinolone acetone was used as monotherapy.
The typical dose regimen of triamcinolone acetonide is 10 mg per linear centimeter of keloid every 2 to 6 weeks until clinical resolution. Triamcinolone acts by a variety of mechanisms to reduce collagen synthesis. Steroids have been shown to bind to glucocorticoid receptors on fibroblasts and downregulate both normal and keloid-derived fibroblasts and inhibit extracellular matrix production.
Adverse effects occur in approximately half of patients treated with triamcinolone and include subcutaneous atrophy, telangiectasia, and pigmentary changes. It should be noted that these side effects frequently resolve without intervention. Adverse systemic effects of steroids generally do not occur with intralesional triamcinolone treatment, but rare cases have been reported.
Figure 4 shows an earlobe keloid before and after successful treatment with intralesional steroids.
19-year-old Hispanic woman with an earlobe keloid before (top panels) and after (lower panels) treatment with steroid injection.
Surgical excision of keloids generally results in recurrence of lesions, with rates ranging from 40% to 100%. Simple excision is believed to stimulate additional collagen synthesis, resulting in rapid regrowth and often a larger keloid.
Radiation therapy has been shown to effectively reduce the recurrence rate of keloids. It works by directly damaging fibroblasts, which alters collagen structure and organization. In vitro studies have shown radiation therapy to increase the rate of apoptosis in keloid fibroblasts, returning the cell population to equilibrium. Ogawa and colleagues studied the efficacy of postexcision radiation therapy while attempting to determine the optimal radiation dose. A total of 109 patients with 121 keloid and intractable hypertrophic scar sites were given electron-beam irradiation at total doses of 10, 15, or 20 Gy, depending on the site. This group was compared with 218 patients with 249 keloid and intractable hypertrophic scar sites treated with the old protocol of surgical removal followed by irradiation at 15 Gy (without variation by site). Median follow-up for the 2 groups were 26 and 23 months, respectively. Recurrence rates in the group receiving the site-dependent radiation protocol were substantially reduced, from 29.3% to 14%.
Acute side effects include erythema, inflammation, edema, desquamation, and ulceration. Chronic changes include changes in pigmentation, skin atrophy, and fibrosis. Despite the presence of a few documented cases, there has been no clear association between radiation therapy and carcinogenesis as witnessed in multiple large-scale clinical trials.
Silicone gel has been approved by the U.S. Food and Drug Administration as an effective adjunct to keloid excision and as prophylaxis to prevent abnormal scarring following elective incisions.[44,45] Silicone gel can be administered either as a topical gel or impregnated elastic sheet. However, one of the primary limiting factors is poor patient compliance. The patient needs to be instructed to cover the entire scar for at least 12 hours each day and ideally up to 24 hours per day, except when the skin is being cleaned. If used correctly, silicone gel has been shown to induce more rapid healing and can be used in conjunction with CO2-laser excision to decrease recurrence rates.[46,47]
Although its precise mechanism of action is unknown, silicone gel is thought to act as an impermeable membrane that keeps the skin hydrated, functioning in a manner analogous to the stratum corneum. Adverse effects of silicone gel include occasional skin maceration, erosion, rash, and pruritus, all of which resolve within several days after gel removal.[48,49]
In addition to silicone gel, pressure therapy following excision is effective and causes minimal adverse effects. The mechanism of pressure therapy has yet to be determined but may be through pressure-induced ischemia that promotes collagen degradation and modulates fibroblast activity.[50,51] Because compression earrings should be worn 24 hours per day after suture removal, patient compliance can be an issue. Nevertheless, regardless of whether it is used on the earlobe or other parts of the body, pressure therapy is simple and highly efficacious with minimal adverse effects.
Laser therapy has been advocated but has not been shown to be effective in managing keloids. Some investigators have combined the CO2 laser with various modalities, including interferon, triamcinolone, and silicone gel. This has resulted in success rates similar to treatment with scalpel excision with adjuvant therapy.[47,52] However, the cost of the laser and the recurrence rate prohibit its use over the scalpel.
Numerous studies have espoused the use of laser therapy in treating keloids. The use of the 585-nm flashlamp-pumped pulsed-dye laser on selected patients has demonstrated efficacy exceeding 75% while incurring minimal morbidity.[53,54] The main problem with laser treatment is that melanin is a competing chromophore; thus, the laser loses efficacy when used on darker-skinned persons. This essentially makes it less useful on the population at greatest risk for keloid formation.
Intralesional 5-fluorouracil is an experimental therapy for keloids that has shown some potential in preliminary trials. 5-fluorouracil is an antimetabolite that inhibits fibroblast proliferation and modestly reduces keloidal scarring.[55,56] A retrospective study on more than 1000 patients examining the effect of intralesional administration of 5-fluorouracil as single therapy for keloids showed a promising initial response. However, the lesion invariably recurred. A high recurrence rate therefore necessitates serial administrations. Adverse effects have been rare and limited to superficial skin irritation.[55,56]
Additional strategies for keloid management reported in the literature include intralesional injection of calcium-channel blockers, cryosurgery, and antihistamines.[57,58,59] Several experimental therapies for abnormal scarring include bleomycin, imiquimod, and cyclosporine. Their use has been restricted to single case reports or small trials and will probably be investigated further.[60,61,62]
Medscape J Med. 2009;11(1):18 © 2009
Cite this: A Primary Care Perspective on Keloids - Medscape - Jan 20, 2009.