Tattoos don’t just leave a mark on your outer skin.
Parts of the design can travel throughout your body.
In fact, nanoparticles from tattoo ink migrate through the body and end up in the lymph nodes, a crucial component of the immune system.
That’s the finding of a study published in Scientific Reports.
The researchers from Germany and the European Synchrotron Radiation Facility (ESRF) in France used X-ray fluorescence to examine the skin and lymph nodes of four human corpses with orange, red, green, or black tattooed skin.
They found tattoo ink had migrated to the lymph nodes. Elevated levels of copper, aluminum, chromium, iron, and nickel in two of the four corpses were also found.
Elevated levels of titanium were found in all four.
“When someone wants to get a tattoo, they are often very careful in choosing a parlor where they use sterile needles that haven’t been used previously. No one checks the chemical composition of the colors, but our study shows that maybe they should,” Hiram Castillo-Michel, PhD, one of the authors of the study and scientist at the ESRF, said in a press release.
Scientists already know that pigments from tattoos can travel to the lymph nodes, as they become discolored with the color of the tattoo.
“What we didn’t know is that they do it in a ‘nano form,’ which implies that they may not have the same behavior as the particles at a micro level. And that is the problem. We don’t know how nanoparticles react,” said Bernhard Hesse, one of the two first authors of the study and an ESRF visiting scientist, in the press release.
Many tattoo inks contain organic pigments used to give color, but they also include contaminants and preservatives like nickel, manganese, or cobalt.
The second most common ingredient used in tattoo ink is titanium dioxide. It’s a white pigment that can be mixed with other colors to create new shades. It’s also commonly used in sunscreen, paint, and food additives.
White tattoos, and by association the use of titanium dioxide, are often associated with itching and elevation of the skin as well as delayed healing.
Does it harm health?
It’s not known whether having tattoo particles in the lymph nodes is detrimental to overall health.
The researchers write that “the deposit of particles leads to chronic enlargement of the respective lymph node and lifelong exposure.”
But Dr. Adam Friedman, an associate professor of dermatology at the George Washington University School of Medicine and Health Sciences, says this may not be bad news for everyone.
“My feeling is that it will be very person specific. Genetics, medical history, even medication use are just a few factors that could play into whether this migration of tattoo pigment will be pathologic,” he told Healthline.
“Think of it this way… Do all patients who get tattoos develop a foreign body reaction aka tattoo granulomas? Does every patient get an allergic contact dermatitis to red dye? No, because every individual’s biological make up is different,” he explained.
Why the lymph nodes?
It may seem odd that tattoo ink would end up in the lymph nodes. They’re located throughout the body in large groupings around the neck, armpits, and groin.
But this is how the lymphatic system works.
It acts as a sewerage system for the body and removes toxins, debris, and other unwanted materials.
This is why a foreign substance like tattoo pigment is engulfed in immune cells and withdrawn from the skin in an attempt to be filtered out of the body through the lymphatic system.
This also explains why a tattoo may not be as boldly colored decades after it was applied.
“We have always known the body’s immune system attacks it [a tattoo] a little bit piece by piece. Have you not seen how in really old people, with a tattoo present for a long time, the ink fades and the margins get blurry? That is from the immune system slowly attacking the tattoo material,” Dr. Whitney High, associate professor of dermatology and pathology at the University of Colorado School of Medicine, told Healthline.
Words of advice
When considering getting a tattoo, it’s advisable to ensure the tattoo artist is following sanitary and hygienic practices, like using sterile tools and disposable gloves.
High agrees that in light of this research, it may also be a good idea to ask questions about the content of the tattoo ink.
“I think it makes sense, knowing the materials migrate, to consider and investigate what is being used as ink. Many of the super dangerous materials, such as cinnabar [red mercury] are not used by most reputable persons anymore, but it never hurts to ask probative questions and perform due diligence, before you take the leap,” he said.
For his part, High says he doesn’t consider himself “a tattoo guy” and will never get a tattoo.
“I think there are a lot of unknowns, and so persons that work in the area, like I do, often just abstain.”