Chemical composition and distribution of tattoo inks within tattoo‐associated keratoacanthoma

Carcinogenic risk of tattoo inks remains unclear and their composition are poorly regulated. Various types of carcinogenic compounds can be found in tattoo inks, including primary aromatic amines (PAA), cleavage products of organic azo-colorants, found in colored inks.1 Many cases of skin cancers occurring within tattoos have been reported, including cases of keratoacanthoma (KA) developed on red ink. Pathogenesis of KA on tattoos remains unclear, and is probably due to multiple factors: trauma induced by the needle during the tattoo itself, inflammatory reactions, ultra-violet radiation, direct carcinogenicity of the tattoo inks and individual background.