The isomorphic (Koebner) phenomenon (KP) may occur in numerous cutaneous conditions and in a wide variety of trauma, including tattooing1. The elective localization of xanthomas in tattooed areas has been described previously23. We report a patient with papular eruptive xanthomas in a recent tattoo without dyslipidemia. The patient has given his consent for publishing all photographic materials.

An otherwise healthy 35-year-old white man presented a recent rash of yellowish non-coalescent papules of the extensor sides of the arms (Fig. 1A), as well as a recent tattoo of the arm (Fig. 1B). Lesions were pruritic and firm to the touch. Physical examination was otherwise unremarkable. A full excision of one of the lesions from a non-tattooed area showed an infiltrate of foamy histiocytes, which favored the diagnosis of xanthomas (Fig. 2). Fasting triglyceride and total cholesterol levels were within normal ranges. Family history for dyslipidemia was negative. Because of the simultaneous timing of the eruption and similar clinical presentation on both tattooed and normal skin, we diagnosed eruptive xanthomas associated with a KP on the tattooed area. After a 2 month follow-up, the lesions were regressing very slowly.

KP has previously been reported with eruptive xanthomas on various occasions (scratches, cat scratches, bee sting, laceration/abrasion injuries and electric burns)45. Following trauma, there may be a delay of several weeks to months before xanthomas appear5. Two cases have been also reported in permanent tattoos34. In one case, xanthomas developed in a 18-month old tattoo2 while in the second report, the tattoo was recent3. Dyslipidemia was diagnosed in both cases and lipid-lowering agents were initiated. Xanthomas may occur in both recent and old scars. In our case, we failed to find any association with dyslipidemia, but normolipemia has been described in several occasions. The reason why xanthomas may locate in scars and tattoos is unknown. Besides, the time relationship between tattooing and eruptive xanthomas is most likely fortuitous. Eruptive xanthomas can be added to the list of curiosities that can locate specifically in tattoos. They may help to diagnose a hidden dyslipidemia.