The most common reactions to tattoo ink are allergic contact dermatitis or photoallergic dermatitis. Contact dermatitis often presents itself as an itchy rash that appears shortly after contact with the responsible substance and will go away once the offending material is no longer in contact with the skin.
Photoallergic dermatitis is a skin reaction to light, often caused by exposure to UV rays. Photoallergic reactions from tattoos are often caused by a reaction between light and a compound in the pigment. Red pigments are the most common pigments to cause allergic reactions.
Tattoos and tattoo inks are subject to regulation by the FDA as cosmetics and color additives. However, the FDA does not currently regulate tattoo inks or the types of pigments used to make them.
The FDA has received several reports of allergic reactions related to tattoos and tattoo inks, some occurring shortly after the tattoo session and others years after the tattoo was done. These reports have prompted the FDA to look into the safety of tattoo inks. As of 2010, the FDA has not approved any tattoo pigment or ink for injection into the skin. Many of the pigments in tattoo inks range from industrial grade printer's ink to automobile paint.
The composition of tattoo pigments is different from color to color and manufacturer. Most tattoo inks contain some type of metal often associated with allergic reactions. Common compounds often found in red tattoo pigments include mercury sulfide, ferric hydrate, sandalwood and brazilwood. Mercury, or cinnabar, is the base metal in the red tattoo and is known to be toxic in large quantities.
To obtain the wide variety of colors available to tattoo artists, different pigments are mixed together to create a new color. People who are sensitive to a compound on one type of ink can still experience an allergic reaction to the mixed color depending on how much of the allergy causing ink is used.
In the case of pink pigment, red pigment is mixed with white; if the tattoo recipient has a sensitivity to mercury or other compounds in either red or white pigment, there is a strong possibility there will be a reaction to the pink. If the color pink is essential to the design of a tattoo, and there is some concern about an allergic reaction, look into a non-metallic based pigment.
The question of safety in relation to tattoos and tattooing has been a concern as tattoos have become more mainstream. All tattoo artists and tattoo parlors are required to follow strict guidelines when it comes to sterilization and disposal of equipment. However, when it comes to the pigment used in tattooing, there is little to no regulation. The contents and composition of the pigments used by tattoo artists vary as each manufacture uses different compounds when creating the pigments. Anyone who is looking into getting a tattoo and has concerns about the potential for an allergic reaction should talk to their artist before their tattoo session. Some pigments have non-metallic options that can reduce the risk of an allergic reaction. If there is a known sensitivity to a specific color or type of pigment, it is important that the tattoo artist is made aware of the allergy so that he can avoid using and mixing colors that can cause a reaction.