Ukraine tattoo
An anti-government protester gets a tattoo in Kiev, Ukraine. Did he get a skin rash?Reuters

They can be colourful, but they're not safe for everyone. A new survey out of New York University has found that tattoos can cause significant skin irritation for a few, sometimes lasting months and even years.

Researchers discovered that 10% of people getting tattoos suffer short-term complications of a rash, infection, swelling, bumps or delayed healing that last for days or weeks.

But 6% of the newly inked have complications that last at least four months, and sometimes for years, reports Eureka Alert. Red ink was used in 44% of the tattoos that caused chronic problems, the highest percentage of any colour.

The researchers, who published their study in Contact Dermatitis, suggested establishing a national database and a protocol for reporting problems.

"We were rather alarmed at the high rate of reported chronic complications tied to getting a tattoo," said lead investigator Marie Leger. "Given the growing popularity of tattoos, physicians, public health officials, and consumers need to be aware of the risks involved." An estimated one in five adult Americans now has at least one tattoo.

"The skin is a highly immune-sensitive organ, and the long-term consequences of repeatedly testing the body's immune system with injected dyes and coloured inks are poorly understood," said Leger. "Some of the reactions appear to be an immune response, yet we do not know who is most likely to have an immune reaction to a tattoo."

Calls to set up a national database

Some skin reactions are treatable with anti-inflammatory steroid drugs, but others may require laser surgery, she said. For stronger reactions, surgery is sometimes necessary to remove tattooed areas of the skin or built-up scar tissue and granular skin lesions, which can cause considerable itching and emotional distress.

She believes a national database could help point to which inks or settings might lead to more complications.

The researchers questioned 300 people with tattoos, ages 18-69, in New York's Central Park in June 2013. People who filled out the survey averaged 4.7 tattoos covering 7.2% of their bodies, but one person had 53 tattoos.