Monday, May 5, 2008

Tattoos: Leaving Their Mark

From Harvard Health Publications

Getting one is pretty safe these days, but what if you have second thoughts and want a tattoo removed? Even today’s pinpoint lasers may not get rid of it entirely.

People have been getting tattoos for millennia, but only recently has tattooing entered the American mainstream. In a 2004 telephone survey of Americans ages 18 to 50, a quarter of those interviewed said they had a tattoo. Now it’s probably more.

With acceptance has come safety, although there’s still a chance of infection, so it’s important that equipment be sterilized and that tattooists wash their hands and wear gloves. In 2004 and 2005, 44 people were infected with methicillin-resistant Staphylococcus aureus (MRSA) by unlicensed tattooists, some of whom fashioned guitar string into needles and used ink from printer cartridges for dye.

The flip side to the popularity of tattoos is increased demand for removal. Laser treatments work, but they’re expensive, time-consuming, and may not erase the tattoo completely.

Bad reactions

Tattoos are more or less permanent because the ink is injected into the dermis, the relatively stable level of skin beneath the epidermis, the outermost layer that’s continually flaking off. They’ve been described as tiny, ink-filled puncture wounds; indeed, tattoos used to be created manually by jabbing a needle into the skin, and they are still done that way illicitly in prisons and elsewhere. But legal tattooists now depend on machines to rapidly inject the ink to just the right depth, about half a millimeter below the surface of the skin. Even with these machines, getting a tattoo may hurt.

Because there’s usually some bleeding, the possibility of getting a blood-borne disease exists for both the tattoo artists and their customers. In the 1950s, New York City banned tattooing after a dramatic increase in tattoo-related hepatitis cases. An Australian study published in 2007 found a link between hepatitis C infections and getting a tattoo in prison, but American health officials have said that there are no data so far in this country linking tattoos to transmission of hepatitis C.

A bigger problem than infections may be the allergic reactions and skin growths.

Some people get henna tattoos, especially while on vacation, because they fade in a couple of weeks. By itself, henna isn’t a problem, but a chemical called paraphenylenediamine is sometimes added to intensify the color. Several case reports describe people having an allergic reaction to henna tattoos because of this darkening agent. Henna-based hair dyes have caused red and itchy scalps for the same reason.

The permanent inks can also be trouble. The mercury in red pigments made with mercuric sulfide (cinnabar) has caused allergic reactions.

Some people have developed strange skin growths — none full-fledged cancers — from permanent tattoos. In 2008, University of Maryland researchers described the case of a 38-year-old man who had a keratoacanthoma, a benign squamous cell growth, sprout from his month-old tattoo. In 2007, doctors in Kansas City reported a case involving a 59-year-old woman who developed a different type of growth, called a pseudoepitheliomatous hyperplasia, in a two-year-old tattoo.

Lasering it away

The permanence of tattoos is part of the attraction, but more than a few people have had regrets. Sometimes it’s not a frivolous situation: cancer patients may get small tattoos to mark the spot where radiation is to be delivered. After their treatments are over, they want the marks removed.

In the past, dermatologists physically removed skin tissue to get rid of a tattoo, cutting or abrading it away. Now they depend on lasers to target and break apart the pigment particles so they get carried away by the lymphatic system. The lasers work in bursts that are nanoseconds long, so damage to nearby tissue is limited. Different wavelengths are used, depending on the color of the ink. Some colors — black, blue — are much easier to remove than others — yellow, orange. Local anesthesia is often needed, and there may be some bleeding.

Laser treatment is a big advance, but it’s far from perfect. Many tattoos can’t be completely removed: a realistic goal is 75% “clearing.” Sometimes the tattoo may turn darker, rather than disappear, because the ink contains titanium dioxide or ferric oxide. The pigments used in tattoos to outline the eyes and lips (sometimes called permanent make-up) can be especially hard to remove. Up to 20 treatments may be needed. In people with dark skin, there’s a danger of the skin turning white, so only lasers with a certain wavelength should be used. Allergic reactions may occur as the pigment particles get liberated from the dermis. Meanwhile, demand is growing for bigger, more complex and vibrantly colored tattoos that will be even harder to remove.

For these and other reasons, there’s interest in tattoo inks that will stay sharp but can be removed more easily. The inks developed by Freedom-2, a New Jersey company, are a possibility. They come encapsulated in tiny polymer spheres and leave the skin quickly after a laser beam bursts open the sphere. Results from animal experiments are impressive. Whether they will work as well in humans and be accepted by tattoo artists and their customers has yet to be determined.

content by:
Harvard Health Publications//Harvard Medical School

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