Pigments in American tattoo inks and their propensity to elicit allergic contact dermatitis

Tattoos have become increasingly common in the United States. Historically, tattoo inks were comprised of metallic pigments, which have the potential to cause allergic contact dermatitis. Data have been lacking on the current use of these pigments in tattoo ink.

Identify pigments currently used in tattoo inks manufactured in or sold by wholesalers in the United States and investigate cases of allergic contact dermatitis caused by these pigments.

Using specific key words, we performed an internet search. Pigment information listed in tattoo product inserts was collated and evaluated.

In total, 1416 unique inks were surveyed. The average bottle of ink contained 3.0 pigments. We identified 44 distinct pigments, of which 10 contained metallic pigments, including iron, barium, zinc, copper, molybdenum, and titanium. The remaining 34 pigments contained carbon, azo, diketopyrrolopyrrole, quinacridone, anthraquinone, dioxazine, or quinophthalone dyes. A literature search revealed that 11 of the 44 (25%) pigments had been suspected to cause contact dermatitis. Five were confirmed by patch testing.

These findings highlight the diversity of pigments currently used in tattoos. Relatively few inks contained metallic pigments to which allergic contact dermatitis has historically been attributed. Patch-test clinicians should be aware of these new pigments.