Treatment of keloid scars

No effective treatment exists for permanent keloid removal. When applied to excised-sites, imiquimod 5% cream reduces keloid recurrence. Case series suggest the tolerability and efficacy of imiquimod 5% application to sites of shaved keloids; however, this has not been verified in placebo-controlled studies. To determine the tolerability and compare the efficacy of imiquimod 5% and vehicle cream in lowering keloid recurrence after shaving.

Twenty randomized, shaved keloids were administered imiquimod 5% or vehicle cream nightly for two weeks, and then given three times a week under occlusion for one month. Pain, tenderness, pruritus and keloid recurrence were evaluated at baseline, week 2, week 6 and 6 months. Tenderness and pain were significantly (p= 0.02 and p= 0.02, respectively) higher at week 2 in the imiquimod group than for those treated with vehicle cream. Pruritus did not attain statistical difference between the groups.

Conclusion: Imiquimod was well tolerated. There was not enough statistical power to detect a significant difference in six-month keloid recurrence rates between the two treated groups. At the present time, there is no therapeutic modality that is 100% safe and effective for the treatment of keloid scars. Recurrence rates for surgical excision of keloids have been reported between 45% and 100%. Keloids represent an abnormal response to injury where the healing environment manifests low levels of interferon alpha and gamma, in addition to other abnormalities. Furthermore, interferon alpha 2b has been shown to be anti-fibrotic by normalizing collagen and glycosaminoglycan production and collagenase activity.

Prior uncontrolled studies have suggested imiquimod 5% cream may be a useful adjuctive treatment to surgery. In an uncontrolled study by Stashower, eight keloids were debulked by tangential shaving and imiquimod cream applied daily for six weeks with no recurrences at one year. In another uncontrolled, pilot study, eight keloids were treated with imiquimod 5% cream daily for 8 weeks. At 24 weeks, 25% (2/8) recurred and imiquimod was relatively well-tolerated. This purpose of this study was twofold: first, to objectively examine the tolerability of treating newly tangentially shaved keloids with imiquimod 5% cream and, second, to evaluate the efficacy in lowering the recurrence rates of keloids.