Yes getting a henna tattoo is indeed pretty, especially if one gets it to mark memories of vacations at far away beaches. But careful. What could only meant as temporary application may actually induce permanent damage to the skin.

On Monday, the U.S. Food and Drug Administration warned the more adventurous to think twice about getting those tattoos because some consumers reported adverse reactions which were severe and lasted way long after the temporary tattoos had faded out.

"Just because a tattoo is temporary it doesn't mean that it is risk free," Linda Katz, director of FDA's Office of Cosmetics and Colors, said in a consumer update.

Henna is a reddish-brown coloring made from a flowering plant that grows in tropical and subtropical regions of Africa and Asia. People have used dried henna, way since the Bronze Age, to dye skin, hair, fingernails, leather, silk and wool.

However, nowadays, a "black henna" has emerged that's being used in place of traditional henna. The US FDA said black henna may be a mix of henna with other ingredients, or may just be hair dye alone.

"The reason for adding other ingredients is to create a tattoo that is darker and longer lasting, but use of black henna is potentially harmful," the FDA said.

To make the henna black, an extra ingredient, a coal-tar hair dye containing p-phenylenediamine (PPD) in added. The ingredient has been known to cause dangerous skin reactions in some people. By law, PPD is not permitted in cosmetics intended to be applied to the skin, according to the US FDA.

Among the consumer-reported skin reactions include skin redness, blisters, raised red weeping lesions, loss of pigmentation, increased sensitivity to sunlight and even permanent scarring. There were even some who had to be brought to hospital emergency room just to be treated of their discomfort.

Reactions vary person. It may occur immediately getting the temporary tattoo, or may occur two or three weeks later.

"What we thought would be a little harmless fun ended up becoming more like a nightmare for us," the father of a 5-year-old girl said after she developed severe reddening on her forearm about two weeks after receiving a black henna temporary tattoo. "My hope is that by telling people about our experience, I can help prevent this from happening to some other unsuspecting kids and parents."

The mother of a 17-year-old girl agreed. "At first I was a little upset she got the tattoo without telling me," she said. "But when it became red and itchy and later began to blister and the blisters filled with fluid, I was beside myself."

A teenager, who got a black henna tattoo on her back, now has skin which looked "the way a burn victim looks, all blistered and raw," according to her mother. A visit to her daughter's doctor said the teenager will have scarring for life.