Triweekly topical 5% imiquimod cream fades experimental tattoos in guinea pigs

Results from a recent study found 5% imiquimod cream to be effective for removing fresh experimental animal tattoos; however, frequent applications of 5% imiquimod cream resulted in fibrosis and the loss of dermal appendages. In the pilot study presented in this article, the dorsal skins of 18 albino guinea pigs were tattooed with black tattoo ink. Fresh and mature tattoos were treated with petrolatum or 5% imiquimod cream daily or triweekly for 16 weeks. Punch biopsies were performed and clinical photographs were taken at baseline, 16 weeks, and 20 weeks to evaluate tattoo ink, inflammation, fibrosis, and dermal appendages. Clinically and histopathologically, tattoos treated with 5% imiquimod cream showed similar fading and loss of tattoo ink that was greater than controls. All animals treated with 5% imiquimod cream retained dermal appendages and showed inflammation and fibrosis. Triweekly use of 5% imiquimod cream effectively faded tattoos in this experimental guinea pig model.