Red ink tattoo reactions:: successful treatment with the Q-switched 532 nm Nd:YAG laser

Background In the South-west Thames region there were an unprecedented number of lichenoid tattoo reactions to red ink in patients who had visited a local tattoo parlour. The red ink was found to contain mercuric sulphide, a compound known to cause allergic reactions. Topical Dermovate((R)) (clobetasol propionate 0.05%, GlaxoWellcome) ointment alone had little impact. Objectives To investigate whether the Q-switched 532 nm Nd:YAG laser could produce permanent flattening of the reaction. Methods This was an open nonrandomized clinical trial. Biopsies were taken from the lichenoid areas within the tattoos. Subjects were patch tested to 1% ammoniated mercury in petrolatum prior to treatment with the Q-switched 532 nm Nd:YAG laser. Laser treatments were delivered at 6-weekly intervals by a single operator. Patients also applied topical Dermovate((R)) between treatments. Therapy was discontinued when the lesions flattened. Clinical photographs were assessed at baseline and prior to each laser treatment. Results Seven patients with Fitzpatrick skin types I-III were enrolled in the study (four females, three males, mean age 39 years). All patients completed the trial. Patch testing to mercury was universally negative at 48 and 96 h. Substantial flattening and depigmentation of the red ink within the tattoos was noted after six laser treatments. No adverse effects were recorded. Conclusions The Q-switched 532 nm Nd:YAG laser in combination with topical Dermovate((R)) ointment is a safe and effective method of treating red ink tattoo reactions.