Why you should avoid ‘black henna' tattoosGeorge Dvorsky3/27/13 1:20pmFiled to: medicineHealthhennahenna tattoosblack hennasciencechemistry19EditPromoteShare to KinjaToggle Conversation toolsGo to permalink Those temporary black henna tattoos may look super cool, but they could seriously mess up your skin. Because they may not actually be made from henna. Advertisement The U.S. Food and Drug Administration issued an alert on Monday saying that the temporary tattoos, when made from “black henna,” could result in adverse reactions. The FDA explains what's going on and what "black henna" is really made of: Advertisement You may be familiar with henna, a reddish-brown coloring made from a flowering plant that grows in tropical and subtropical regions of Africa and Asia. Since the Bronze Age, people have used dried henna, ground into a paste, to dye skin, hair, fingernails, leather, silk and wool. This decoration—sometimes also known as mehndi—is still used today around the world to decorate the skin in cultural festivals and celebrations.However, today so-called "black henna" is often used in place of traditional henna. Inks marketed as black henna may be a mix of henna with other ingredients, or may really 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.That's because the extra ingredient used to blacken henna is often a coal-tar hair dye containing p-phenylenediamine (PPD), an ingredient that can cause dangerous skin reactions in some people. Sometimes, the artist may use a PPD-containing hair dye alone. Either way, there's no telling who will be affected. By law, PPD is not permitted in cosmetics intended to be applied to the skin. Reactions can include blisters, redness, sensitivity to sunlight, raised red weeping lesions, and permanent scarring.According to MedWatch, there have been numerous reports from people who have reacted poorly to the tattoos, including a case involving a 5-year old girl who developed extremely severe reddening two weeks after: Sponsored "What we thought would be a little harmless fun ended up becoming more like a nightmare for us," the father says. "My hope is that by telling people about our experience, I can help prevent this from happening to some other unsuspecting kids and parents."More at the FDA here and here. Advertisement Images: Shutterstock/Olena Zaskochenko; FDA.