Henna hazard: Chemical causes ornate allergies

Harsh dye can swell popular tattoos into itchy, blistery swirls and shapesA women has never been one for tattoos. But when her daughter Kim begged to get a henna tattoo on a family vacation to Cancun a few years ago, she thought it couldn’t hurt because its tempprary, and Kim want to show off to her friends back home. But just two days later, the tattoo of a cute little bug had swelled into an itchy, bubbling blister on Kim’s upper right arm. “I was scared to death,”says her mother, who’s 43 and lives with her family in Cary, N.C. “I thought, she’s 9 years old and she’s going to be scarred for life.” The American Academy of Dermatology recently issued a warning that a chemical found in black henna tattoos can cause a severe allergic reaction, causing the skin to redden, swell and blister — but only where the henna is applied,people with bubbly blisters in shapes like suns, stars and flowers.As henna tattoo become very populer in the last few years, sometimes peddled at summer carnivals and concerts, dermatologists report increasingly treating patients,especially teen girls and young women, with these often elaborate looking allergic reactions.“Just because they’re temporary, people think they’re safe,” says Dr. Sharon E. Jacob, a dermatologist at the University of California, San Diego. Natural henna vs. black hennaWhile true henna is made from harmless plants, black henna uses a chemical called para-phenylenediamine, or PPD, which makes the tattoo dry quickly and last longer — and in some cases, that’s much, much longer. “These skin allergies themselves are not dangerous,” says Dr. Colby Evans, a dermatologist in private practice in Austin, Texas. “But they can cause scarring or darkness to the skin that can be permanent." There are also lifelong allergies to some medicationsBut Evans and other dermatologists warn that just one bad reaction to black henna can be enough to cause permanent sensitivity to PPD, and that allergy can cross-react with chemical relatives in certain anesthetics and medications for heart disease, hypertension and diabetes. “The allergy you can develop is lifelong,” says Jacob. But she’s found that people, especially teens, are generally unimpressed by her warnings of reactions to medication, so she reserves this for the kicker: “It may mean you can never dye your hair again.” Experts say there are a few easy ways to tell the difference between reall henna and black henna.For one,henna is never black — it’s red, which darkens to a brownish color on the skin as it dries. Real henna starts to fade away within a few days, so be wary of a henna tattoo artist who boasts of tattoos that will last any longer than that.