Because manufacturers of tattoo ink are not required to list what ingredients are used in their products, many tattoo artists themselves do not know the specific ingredients. There can be a risk of skin reaction to tattoos, especially to those who have sensitive skin.
While tattoo ink needs approval from the Food and Drug Administration, the FDA itself has admitted to not strongly regulating the content of tattoo ink. Some ingredients in the ink may be FDA approved, but not necessarily for tattooing.
Tattoo ink can cause a variety of skin reactions ranging from an itchy rash at the tattoo site, small bumps called granulomas or an overgrowth of scar tissue known as keloids. Although these reactions are minor, they can happen years after the tattoo was applied. Red ink tends to be the most common offender, although any color can cause a reaction.
While skin reactions can occur, they are not a common effect of a tattoo healing. If itching persists years later or if there is any redness, swelling or pus drainage on the site soon after you have been tattooed, seek medical attention from a dermatologist right away; these can be signs of an infection.
Although there is no sure way to determine if a reaction will occur, there are preventive measures that can be followed. Ensure that the tattoo studio employs trained artists who properly use disposable equipment, follow health standards and are licensed.
Both the Mayo Clinic and Centers for Disease Control insist that all non-disposable equipment be heat sterilized and the tattoo artist's work area be wiped down with a disinfectant after each customer. Keeping the skin around the tattoo area clean and following the artist's after-care instructions can help prevent future problems.