Topical Imiquimod as an Adjuvant to Laser Removal of Mature Tattoos in an Animal Model

BACKGROUND: Lasers are a commonly employed method of tattoo removal; however, numerous treatments are often needed and laser treatment may fail to eliminate the tattoo completely. It has been shown in animal studies that topical application of imiquimod cream, alone, fades tattoos. It is suspected that the combination of both imiquimod and laser treatment will result in enhanced tattoo pigment clearance. OBJECTIVE: The objective was to evaluate the efficacy of topical imiquimod cream as an adjuvant to laser removal of mature tattoos. METHODS: Fourteen albino guinea pigs were tattooed with black ink, then randomly assigned into two groups: one underwent sequential laser treatments with a Q-switched alexandrite laser in conjunction with triweekly applications of 5% imiquimod cream, while the other group underwent laser therapy alone. Subjects were evaluated with clinical photographs and skin biopsies after six laser treatment sessions. RESULTS: The combination laser and imiquimod treated group was clinically and histologically rated as having less pigment than the tattoos that were treated with laser alone (p=.012 and p=.047, respectively). Adjuvant imiquimod treatment had greater inflammation (p=.002) and fibrosis (p=.002) on posttreatment skin biopsies. CONCLUSION: Imiquimod appears to be a useful adjuvant to experimental laser tattoo removal in guinea pigs.