Inside the chemistry of tattoos and tattoo removal

Regardless of artistic skull or gauche fairy, full-sleeve or behind the ear, all tats are the same beyond the aesthete. Sure, getting inked may just seem like something you do on a Friday night with your tax return, but the science of tattoos and their removal causes biological and chemical changes in your skin and can affect your immune system.

Pam Fletcher, a doctor of nursing practice from University of Cincinnati, said that although she doesn't advocate for decorative tattoos, instead favoring medical and cosmetic tattoos, she finds them interesting on a biological level.

"You're doing something to the largest organ of the body and the complex interconnections of the immune system and the skin and tattoo … it's fascinating," Fletcher said.

Skin has three layers. The top is the epidermis, the middle is the dermis and the bottom layer is the hypodermis. Tattoos are collections of pigmented ink particles suspended in the dermis that are too large and too deep to be absorbed like other inks or ointments placed on the epidermis.

When someone first gets a tattoo, his or her body's immune system detects the foreign particles and sends granulomas to wall off the tissue surrounding the inked dermis. The body has no mechanism for absorbing it, Fletcher said. The granulated tissue, i.e. the walls, eventually forms a permanent connective tissue called collagen. As the years and decades pass, the ink settles deeper into the dermis. This is what causes tattoos to fade and can make old tattoos harder to remove, Fletcher said.

Before the use of laser, tat removal was a little less scientific and included abrasive and intrusive processes. While Fletcher suggests that people looking to remove tattoos seek out a dermatologist for their removal, there are many laser and cosmetic clinics that do not necessarily remove tattoos medically.

Laser tattoo removal is also called photothermolysis. The way it works is as such: Light moves in waves. These waves correspond with certain colors, i.e. the color spectrum and rainbows. Tattoo removal takes advantage of this by using lasers that beam the frequency absorbed by the colored ink of the tattoo. When a laser hits the pigmented skin, the ink is broken into smaller particles that are then very slowly absorbed by one's immune cells, called macrophages, – so slowly that after a laser treatment the tattoo may not look any different for weeks – and detoxed through the liver. It will take anywhere from six to eight weeks before a laser removal specialist can touch up whatever pigment is left. According to Jennifer Mundt, a naturopathic doctor at Delete Tattoo Removal & Laser Salon in Phoenix, professional tattoos can take up to 10 treatments to remove and amateur pieces take about five.

"In most of the [laser] filters, you're preserving the normal pigment of the skin, but there are some colors, like the yellows and the reds, where you can find a little bit of hypopigmentation, where the tattoo comes off, but the skin where the tattoo was is a little lighter than the surrounding tissue," said Suniel Jain, a naturopathic physician at Rejuvena Health and Aesthetics.

This is what can make removing a tattoo difficult on pigmented skin, the colors of which are measured on a Fitzpatrick Scale, which ranks skin tones from one to six, six being the darkest. Lasers see color, however, sometimes a laser may remove the melanin, which makes one's skin dark, in addition or instead of the tattoo ink, Mundt said, who has been removing tattoos since November 2010. For people with darker skin, Mundt said she uses a "delicate" wavelength called a 1064 nanometer wavelength.

Mundt said there's nothing necessarily toxic about the removal detox, but that the ease with which one's body removes ink depends on a person's health and immune system. Also, large tattoos, Mundt said, cannot be done in one sitting because the detox may be too much for the body to handle all at once. People who have autoimmune diseases, which some inks are theorized to cause, can have an allergic reaction to the removal of certain inks, Mundt said. Red dyes are commonly reacted to in the form of sarcoids, which are a granulomatous and lesion-causing in certain red dyes, Fletcher said. Such tattoo spots need to be removed surgically.

"We have to be really careful to make sure the person is healthy enough to go through this and that their immune system isn't going to freak out on us because they can get really sick from this," Mundt said of the removal process.

Mundt, as a naturopathic doctor, takes the health of a person and their skin seriously and said she often helps them with supplements and vitamins to ensure they're getting the most out of their removal treatments.