Tattoos and body piercing are increasingly popular.  A recent survey in the U.S. found that four in ten people age 18 to 29 have at least one tattoo. The figure in Canada is closer to 20 per cent. Nearly one in four Americans has a body piercing in locations other than the earlobe. New recommendations by the American Academy of Pediatrics helps teens and their parents manage the risk.

The guidelines are aimed at pediatricians, family doctors and nurse practitioners who can be expected to get questions from teens and from parents. It contains a comprehensive set of "dos and don'ts" regarding tattoos, permanent makeup, henna and temporary tattoos and tattoo removal. There's a lot on body piercing, including the approximate healing times for various sites. For instance, tongue piercing take three to four weeks to heal, while nipple piercing can take up to four months. It includes useful tips like wearing a curved barbell instead of a ring through a new navel piercing to reduce skin irritation and scarring.  

There's also a section on ear stretching, which is a common cultural and religious practice in parts of Africa, Eurasia and the Americas. There's also a section on scarification, which is cutting, burning or branding words or images into the skin.

The number one reason why the American Academy of Pediatrics published these guidelines now is that tattoos, body piercing, stretching and scarification are now mainstream ways of self-expression. A 2016 Harris Poll found that three in 10 adults in the U.S. has at least one tattoo – up 20 per cent in just four years. A study of high school students in Quebec found 27 per cent had body piercing and 8 per cent had tattoos. In the Harris Poll, 86 per cent say they didn't regret getting one; 30 per cent say it makes them feel sexier, 25 per cent say more attractive.

Despite the popularity, surveys of college students show they may be unaware of health risks. For instance, most know about the risk of HIV from dirty needles, fewer are aware of other viral infections like hepatitis C and hepatitis B. They aren't well-versed in the risk of contracting tetanus, staph infections as well as non-infectious complications. Surprisingly, even medical students who have undergone piercing are relatively unaware of complications. The authors of the guidelines think doctors are well-placed to bridge the information gap.

Just how risky is tattooing and body piercing? The rate of complications from tattoos is not known but is probably low given the large number of tattoos placed every day and the paucity of complaints. There is the occasional cluster of infections usually traceable to faulty sterilization methods or a tattoo artist who has become a carrier for Staphylococcus aureus bacterium. Bacterial infections range from abscesses to cellulitis; these usually appear between four and 22 days after getting the tattoo. Other kinds of infection include mycobacteria.

Researchers have suggested that tattoo ink may be toxic. A study published this week talks about nanoparticles of tattoo inks that consist of organic pigments as well as preservatives and contaminants. According to the report, nanoparticles can travel to the lymph nodes. The particles include titanium dioxide, a white pigment used to lighten various pigments in tattoo ink. There are no reliable estimates of complication rates for body piercing. There are case reports of infection, bleeding, hematoma formation, allergic reactions and scarring. If a large blood clot forms in the ear, it needs to be drained and packed by an ear, nose and throat specialist to prevent the formation of a deformed or cauliflower ear.

In the U.S., individual states have regulated tattooing practices to address public health concerns. The National Environmental Health Association adopted common standards on sanitation and infection control. As of 2012, 41 states had at least one statute regulating tattooing. Still, 72 per cent of states do not effectively regulate sanitation, training and licensing and infection control. This is one of main reasons why the American Academy of Pediatrics is urging doctors to learn about regulation at the local and state level.  

In Canada, B.C., Alberta and Ontario have standards for tattooing and body piercing. Some provinces have not regulated practices. Still, Health Canada has created a set of infection control guidelines for people in the industry, and the provinces are free to use powers under the Public Health Act to protect the public. Tattoo ink is classified as a cosmetic pigment, which means it is not approved by Health Canada. That means it's the responsibility of the manufacturer or importer to meet the requirements of the Food and Drugs Act and Cosmetic Regulations. A spokesperson for Health Canada told CBC News this is true of all tattoo ink, including inks that contain nanoparticles.

If you're concerned about safety, and want to know what to look for in a tattoo or body piercing ship, some provinces like BC have detailed guidelines that give you the general principles. The shop should be as clean as a dentist's office. There should be a stations for hand washing and for cleaning instruments. The equipment should look like it's durable and in good repair.  

The provider should ask for consent to do the procedure, and explain what's being done, the possible side effects and both the long- and short-term health risks. They need to get your contact information for public health in case of an outbreak. Forget what you've seen in the movies about waking up with a new tattoo and no clue. You can't give consent if you're intoxicated. The provider should wash their hands and put on a new pair of disposable gloves. New needles should be used, and you should see the person open the package right in front of you.  

Doctors recommend that teens discuss tattoos with their parents beforehand - and with good reason. Depending on the size, laser removal of tattoos can cost hundreds and even thousands of dollars to remove.