Henna is an ancient art form dating back more than 5,000 years to the Middle East, South Asia and Africa. In recent years, it has also gained popularity in North America.

Vineeta Rajani has been captivated by henna since she was a young girl growing up in India. Today, she makes her living as a henna artist in Dartmouth. She hand creates her dyes, using all natural materials - something not all artists can say.

“I want to be sure what’s in the paste,” says Rajani. “Someone might be allergic to say essential oils, like clove oil, that you have to be very careful when you’re using it in your henna paste.”

The practice involves creating a paste from natural henna powder, essential oils, water, and lemon juice. The paste is then painted on the skin, allowed to dry, then brushed off. What’s left is an intricate pattern in a colour ranging from orange to dark brown, but never black.

Halifax-based dermatologist Dr. Kerri Purdy says there is an ingredient in black henna, or temporary tattoos, that can give the recipient more than they bargained for.

“The specific component that most people would be allergic to is something called Para-phenylenediamine, or PPD which we call it for short,” says Purdy.

A reaction to PPD can cause redness, itching, and blistering of the skin, similar in appearance to eczema.

“If you only had a small, small area, you could probably use some topical steroid cream to help settle it down,” says Purdy. “If people had maybe both hands all painted and they were having a severe reaction, occasionally we’d even need to use steroids by mouth.”

Natural henna should be dark green in colour and before having henna paste applied, Rajani recommends asking the artist exactly what is in it.

“Another thing to be very careful of is to ask your artist how long will it take the henna to develop?” says Rajani. “Natural henna will take 12 to 24, maybe 48 hours to develop completely to get a darker stain, but if they say in two to four hours you’ll get a dark stain that will be black in colour, that’s another pointer right there.”

Rajani knows firsthand what can happen when unnatural ingredients are used in henna paste.

“We tried that chemical stuff, which immediately burned the skin and it was horrible,” she says. “I still have a little burn and that happened almost 12 years ago.”