5 Things You Didn’t Know About Tattoos and Your Health

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At its core, tattooing is a primal practice. But do we really understand it?

The oldest tattoos on record belonged to Ötzi, the European Tyrolean Iceman who died in 3250 B.C. After discovering his body on the Austrian-Italian border, anthropologists noticed bracelet-like markings on his wrists and over 60 other primitive tattoos on his arms, legs, and torso.

Thousands of years later, we’re still poking shapes and symbols into our skin. It’s estimated that three in 10 Americans have at least one tattoo. Most of the to-be-inked population does some research on reputable shops and artists, but how much does the average consumer know about what the tattooing process does to the skin and body?

We spoke with Dr. Arisa Oritz, a board-certified dermatologist and director of laser and cosmetic dermatology at UC San Diego Health, to better understand tattoos from a health perspective.

Here are five things you may not know about tattoos.

Not all ink stays put.

A tattoo artist’s needle repeatedly punctures the skin – in some cases, more than 100 times a second – delivering ink into the dermis, the second layer of the skin. “There are cells that are part of the immune system that come in and engulf the pigment,” Ortiz explains, keeping some, but not all, of the ink within the outline of the tattoo.

“Not all the pigment will necessarily stay where you put it,” Ortiz says. “It can end up in the lymphatic system and your lymph nodes,” where it remains indefinitely. The long-term effects of lingering ink are unknown, but Ortiz notes that tattoos, in one form or another, have been around for ages. “It’s probably nothing too grave or we’d likely know by now,” she says.

Tattoos can mess with medical testing.

However, that rogue ink can interfere with certain medical tests, specifically dermatological body scans. If, for example, you have melanoma and you’re being worked up for possible metastasis, the spread of cancer from the primary site to other parts of the body, you may undergo what turns out to be an unnecessary biopsy. “It can confuse the clinical picture because the tattoo pigment in the lymph nodes could look like potential metastatic melanoma,” Ortiz says.

Inked skin may sweat less.

A recent study conducted by the Department of Integrative Physiology and Health Science at Alma College in Alma, Mich., found that participants — 10 healthy, adult men — produced less sweat on the tattooed portions of their body than on un-inked skin. Additionally, the sodium concentration of sweat collected from tattooed skin was significantly higher.

More research is needed to better understand the impact of tattoos on the body’s naturally cooling system, but scarring of the sweat glands may be to blame for the sweat reduction. “The process of that needle going in and out of the skin multiple times to deliver the ink often times causes scarring to the skin,” Ortiz explains. “Scarring can be camouflaged with ink, so you don’t notice it as much.”

You should rethink a red tattoo.

A new tattoo can trigger an allergic reaction. Symptoms range from bumps and skin thickening to more systemic reactions, like an overall feeling of fatigue and weakness. But not all tattoos are equal offenders.

“Of all the tattoo inks, red seems to be the most mischievous,” Ortiz says. Historically, red inks used mercury. Even though that’s no longer the case, Ortiz explains that the majority of the allergic reactions she sees are, for unknown reasons, from tattoos using red ink. “So if you’re thinking of getting a red tattoo, I’d probably discourage against it,” she says.

Regulation is a Concern

Technically, tattoo ink is regulated by the FDA; if an ink is sold in the marketplace, tattoo shops and artists assume that it’s non-toxic and safe for injection into the skin. But Ortiz explains that, because the FDA’s realm of responsibility is so vast, not much is currently done to enforce regulations. “There’s no specific procedure these ink companies have to go through in order to get their ink approved,” she says. “I’m not against the ritual of tattooing. My concern is that the inks are not regulated. Until then, safety is in question.”