Her Body: Are You Allergic to Your Hair Coloring?

A friend of ours inspired this column, but we're betting that a lot of readers will identify with her problem. She is a respected professional with a national reputation in her field. In fact, she has every reason to feel secure—except for one not-so-little dilemma. Our friend, who is in her 50s, has been coloring her gray hair for years without a problem. But recently, she started to break out in a nasty rash every time she got her hair done. With each visit, the rash became a little worse. Her hairdresser tried a number of different products and all provoked some kind of allergic reaction. The solution should be simple: throw out the hair dye and go natural. But at the place where our friend works, youth is highly valued and she thinks that looking her age could put her job in jeopardy. It's certainly unfair, but she says that's the way it is in her office (and probably in a lot of other offices as well). She asked us for help.

Even before she called, we'd been noticing that there are virtually no gray-haired women in the communities where we live—New York City and Washington, D.C. —although there are plenty of women over 40. And we all know why. The cosmetic industry estimates that between one half and two thirds of adult American women and many men regularly use some kind of hair-coloring product—and sales are steadily climbing as the baby boomers age. (In case you were wondering, brown is the most popular shade.) More young people, with no gray to hide, are also coloring their hair.

As the number of people who have been coloring their hair for many years increases, so does the chance that many will develop allergic reactions like our friend's. Hairdressers are at risk as well. The technical name for the rash is contact dermatitis. No one keeps track of cases nationally, but a recent study in the British Medical Journal found that the number of patients with this problem in one London clinic doubled in just six years. Our friend's symptom, a rash on or around the scalp, is typical. In severe cases, patients can develop facial swelling. The reaction isn't immediate but generally appears within several hours of the initial exposure and can take more than a week to resolve without treatment. In severe cases, a doctor may prescribe oral corticosteroids to speed healing, says Dr. Vincent DeLeo, an expert on contact dermatitis at St. Luke's Roosevelt and Beth Israel Medical Centers in New York.

Although you can develop an allergy to many ingredients in hair coloring, the most likely culprit is a chemical called para-phenylenediamine (PPD). It has been a major component of most hair-coloring products used in the western world since the 1880s and has caused problems almost since it was first developed, according to the American Contact Dermatitis Society—which named PPD its "allergen of the year" in 2006. Because of its potential to cause an allergic reaction, PPD was banned in Sweden, France and Germany for most of the last century (it re-entered the market after the formation of the European Union). PPD remains popular as a permanent dye because it produces a natural color that doesn't fade with shampooing.

Allergic reactions to PPD can vary by race, says Dr. Amy McMichael, associate professor of dermatology at Wake Forest University School of Medicine in North Carolina. In Caucasians, McMichael says, the most common symptoms are redness and blistering at the hairline. African-Americans are more likely to exhibit scaly patches on their skin when they're allergic, McMichael says. New evidence indicates that African-Americans may be particularly vulnerable to PPD allergies, perhaps because they tend to use darker colors and the darker the color, the more PPD a dye contains. A recent study at the Cleveland Clinic found that black men had a significantly higher number of reactions to PPD than Caucasian men. Doctors are also seeing more contact dermatitis among men who color their beards.

Hair coloring isn't the only source of PPD allergies. Dermatologists are also concerned about the growing popularity of temporary tattoos, sometimes called black henna tattoos. Often offered at carnivals and beach resorts, these tattoos last for weeks or even months. Unlike natural henna, which rarely triggers an allergic reaction, black henna contains PPD. "PPD is not supposed to be used directly on the skin, and these tattoo inks have much higher levels of PPD than hair dyes," says DeLeo. "The other problem is that it stays on the skin. You don't rinse it off." People who develop an allergic reaction to these tattoos are very likely to react to PPD in hair coloring.

Now that we know what caused our friend's problem, we wanted to help her solve it. McMichael suggested using semi-permanent coloring, which contains less PPD and causes fewer sensitivities. Temporary hair coloring, which washes out with each shampoo is another option. Before going back to the hair salon, however, McMichael thinks women with allergic reactions should get a patch test. "You should make sure that it is not perfumes or other additives that you may actually be sensitive to," she says. DiLeo suggests trying natural henna or Elumen (manufactured by Goldwell), the only permanent hair dye he knows of that contains no PPD. Allergies develop over time, so even if your hair product isn't causing any problems now, it might trigger a bad reaction in the future. To avoid that, DiLeo says women might consider going for a lighter color (so you're exposed to less PPD), looking for products with less PPD, or asking your stylist to dilute the dye.

Our final expert on this subject is Pat's hairstylist, Tina Sounrut of the Salon at Saks Fifth Avenue in Chevy Chase, Md., who has long favored the semi-permanent dyes, partly for safety reasons. She told Pat none of her clients have ever told her they've had a bad reaction to hair-coloring products, but she has heard some complain that their scalps itch after the dye is applied. "Sometimes, customers will ask for something to scratch their scalps with, something like this," she says, holding up the handle of a rat-tail comb. "But I always say no … because it could be dangerous. You don't want to take the chance that they could cut or scratch their scalp and create an opening to the skin that the chemicals could enter." Just thinking about that prospect makes us squirm.