Tattooing and psoriasis: a case series and review of the literature.

BACKGROUND: Koebner phenomenon (KP) affects from a quarter to a third of the patients with psoriasis and can occur on tattoos MATERIAL AND METHODS: We retrospectively reviewed a case series of seven tattooed patients with an isomorphic response on their tattoos or partial psoriasis patches on their tattoos. We collected the demographic data, the past history of psoriasis, the clinical presentation, and the outcomes. We also performed a review of the literature. We tried to classify the different clinical profile of KP/psoriasis on tattoos accordingly.

RESULTS: Six men and one woman with a median age of 36 ± 6.4 years old were included. Five disclosed a KP in a recent tattoo within days to 1 month after its completion. Fifteen additional cases were collected from the literature (8 men, median age 22 ± 8.2 years old). The delay of psoriasis flare-up after tattooing was rather short, from a few weeks to several months. We found a high variability in the clinical presentation with five clinical subtypes/profiles of psoriasis on tattoos. A possible confusion between "genuine" KP on tattoos and the coincidental occurrence of psoriasis patches on tattoos is possible in some cases of the literature. Patients were mainly managed locally, rarely by systemic treatments or biologics.

CONCLUSION: Koebner phenomenon on tattoos may occur in patients with psoriasis under various forms. The evolution is benign, and psoriasis is not a contraindication for tattooing, but patients need proper counseling before getting tattooed.