A study reveals that tattooing allows metal particles to penetrate deeply into the tissue from the needle. The researchers identified heavy metals such as nickel and chromium in the skin and even in the lymph nodes. These metal particles are apparently caused by abrasion of the tattooing needle – particularly when using an ink containing titanium dioxide. The possible consequences of this contamination by the metal could be allergic reactions.
From wood to real body art, even the ancient Egyptians and the man of the glaciers "Ötzi" enjoyed the tattoos. And still today, tattoos are again in fashion. Between 8 and 24% of the European and American population wears colors on the skin. In Germany too, almost every tenth is tattooed.
Metals at the origin of allergies
However, the hype surrounding tattoos often forgets that these also represent a risk. Thus, intact skin is injured during the tingling process, creating a gateway for bacteria and other pathogens. In addition, over time, tiny colored particles can come off tattoos. They then wander into the body and accumulate among others in the lymph nodes – with unclear consequences.
Another side effect of body painting: it often causes allergies. Until now, researchers have assumed that these reactions were primarily responsible for color pigments contaminated with heavy metals such as iron oxide. But it turns out that there is another potential source of allergens: tattoo needles.
Needles contain nickel and chromium
"Although tattoo needles contain large amounts of sensitizing elements such as nickel and chromium, their influence on metal deposits in the skin has not yet been studied," says Ines Schreiver of the Federal Institute for Risk Assessment (BfR) and colleagues. To change that, the scientists analyzed samples of skin and lymph nodes from tattooed individuals using nanorug fluorescence.
Indeed, the results revealed that micro and nano-sized metal particles were found in the skin and lymph nodes of tattooed subjects. These particles consisted mainly of a mixture of nickel, chromium and iron. The latter aroused the suspicion among researchers that these metals could not come from tattoo pigments, but from the tattoo needle. Because usually these needles are steel with a nickel share of 6 to 8% and 15 to 20% of chromium.
Pig skin experiments have confirmed this hypothesis: if the researchers used a tattooing agent containing white pigmented titanium dioxide (TiO2), the tattooing process deposited particles containing nickel and chromium into the skin. In addition, the needle exhibited significant signs of abrasion. Because the ink itself contained no metal and could therefore be excluded as a source, it was clear: "The metal particles are introduced by the pure mechanical stress of the needle into the skin," explains the team.
On the other hand, in the same procedure with carbon black ink, the effect was not detectable in this form. Schreiver and his colleagues explain this by saying that TiO2 ink is known for its abrasive properties. Unlike carbon ink, it can thus promote seizing of metal particles.
Needle particles in inflamed skin
So, at least when using an ink containing titanium dioxide, heavy metals can pass from the needle into the skin and from there into the rest of the body. But is there also a link with allergies? The scientists examined this with samples from a tattooed patient who had developed an allergy to his tattoo and who had undergone a nickel test.
The result: the inflamed skin contained not only iron oxide pigments, but also abraded steel particles and abraded tattoo needles. "The skin of this patient contains two potential sources of nickel: high-nickel needle abrasives and low-nickel iron oxide pigments," the researchers reported.
Additional research is needed
"The evidence presented in our study raises the question of whether the rubbing of tattoo needles on metal – such as iron oxide pigments – could play a role in allergic reactions to tattoos," said Dr. 39, Schreiver team. Further investigations should now show how accurately abraded needle particles should be evaluated in relation to skin allergies. (Particle and fiber toxicology, 2019, doi: 10.1186 / s12989-019-0317-1)
Source: Federal Institute for Risk Assessment