Freshly inked tattoos are believed to have triggered keratoacanthomas in two patients, with the nodules appearing within a few days of the ink being applied, Dutch doctors report. 

Unlike most previous reports, where the keratoacanthomas (KAs) were linked to red ink, the latest cases involved black and grey tattoos, say clinicians from the Haaglanden Medical Center in the Hague.

And in one case, an additional lesion grew outside of the tattoo area.

“This implies the need for further studies to explore why tattoos trigger the development of KAs,” the clinicians wrote in BMJ Case Reports.