As evening fell and Hurricane Sandy began to lash the region, a large brick house in Falls Church blazed with festivity.Women danced in brightly colored satin and lace robes, long streams of mint tea poured into glasses and Keltoum Azzar carefully drew an intricate checkerboard pattern across the palm of a teenage girl.

It was Eid al-Adha, the Muslim Feast of the Sacrifice, and Azzar, 62, and about 20 friends and relatives, mostly natives of Morocco, were celebrating with a tradition that spans three continents, multiple religions and several millennia: decorating the body with henna.

The practice, which temporarily dyes the skin using a paste made from ground-up leaves of the henna plant, is painless; and with a life span of about two weeks it is far less of a commitment than a tattoo. Among the international mix of residents who make up the greater Washington area, people such as Azzar have brought this old tradition with them to the new world.

“My mom, she likes henna, and every Eid, every holiday, she did the henna for us,” said Azzar, who moved here in 1995. An executive secretary in Casablanca, Azzar didn’t do much henna there — in Morocco, women have shopfront businesses to take care of henna needs. “But when I came here, I started to do henna, because everybody, they asked, ‘We need henna. We need somebody to do the henna.’ ”

The use of henna cuts across a vast geographical swath, from India to Morocco to sub-Saharan Africa and Eastern Europe. Different regions have their own designs and techniques: the paste might be mixed with lemon or scented oils and applied with delicate pointed sticks or squeezed out through small cones.

In India, the tightly woven patterns incorporate paisleys, flowers, lattice and peacocks. In Persian Gulf states, the designs are more ribbon-like and floral. In Morocco, they often incorporate geometric shapes such as diamonds and triangles.

In the United States, where henna art has blossomed in recent years, many artists expand beyond traditional wedding and feast days, bringing their art to schools, fairs and festivals.

“It’s the beautification of women, so people like that,” said Khadija Dawn Carryl, a Canadian henna artist who runs Henna Sooq, a home-based henna business in Elkridge. Carryl does henna for weddings and sweet 16s and on pregnant women’s bellies. “It’s a natural product — it’s organic — and it’s very intimate.”

Who does henna — and under what circumstances — varies across cultures. In Morocco, it’s a feminine thing, but in neighboring Algeria, men use it to stain their feet. Henna has been used to decorate horses’ tails and babies’ hands and sprinkled into corners of rooms to placate evil spirits — but it is perhaps best known as an adornment for brides.

Last month in Fairfax Station, Ashley Singh, 26, spent hours with her arms and legs frozen in position as an artist applied henna for her coming wedding.

Singh’s parents’ house filled up with friends and relatives, who oohed and ahhed over the designs as her groom, Roby Thomas, 26, placed morsels of pakora and chaat into her mouth so she could eat without smearing the wet mud.

“It’s funny, because even though we all grew up here, we’re still very traditional,” said Singh, a Sikh who met Thomas, whose family members are Catholics from the Kerala region of India, when they were high school students in Northern Virginia.

Bhavna Naik, the artist, drew Singh’s face on one hand and Thomas’s face on the other. But one old tradition was absent: the name of the groom subtly concealed within the henna design.

“In traditional days of arranged marriages, there was no way for them to break the ice, so they would hide the groom’s name, so they would have to get close to each other,” Naik said, adding that once they were alone, the husband could search for his name on his bride’s body. (Singh quickly noted that she and Thomas did not need help getting to know each other.)

Naik, who grew up in Mumbai and lives in Clarksburg, has done henna since she was a child but started professionally in February. At a recent exhibit at Strathmore called “Skin,” she drew on visitors’ hands, offering tips on how to care for the henna until it dried.

“Don’t bump into anything, because it will get smashed,” she said. “And please, never wrap yourself with plastic bag because the henna will smear.”

As the practice has gained popularity in the United States, it has been adopted — and adapted — by artists who don’t come from henna cultures. Elisa Rodero of Columbia took a course at the Smithsonian that taught her to grind the dried leaves into powder and mix it with water and lemon juice.

Rodero can do Indian bridal henna, but at the festivals and fairs where she works, people generally request tattoo-style images such as peace signs, dragons and bats.

“It’s more like, ‘Look, I can get this fun temporary tattoo’ — something they can get at the boardwalk or the beach,” she said.

Some cultures believe that the artist garners blessings by applying henna to others, and Rodero evinces this. “Sitting down face to face across from somebody, you’re physically touching them, you’re putting some creativity toward someone,” she said. “There’s something incredibly peaceful and enjoyable about the experience.”

Some see it as a test run for a permanent tattoo, she said, adding that with henna, “you can change the look of it all the time, like changing accessories.”

Noam Sienna, 23, a teacher and henna artist who lives in Takoma Park, also did not grow up with henna, but he devoted his college thesis to Jewish henna traditions.

“It’s not religion-based; it’s really place-based,” he said, adding that Jews from the Middle East and Africa traditionally used henna to mark life-cycle events such as a birth, a new job and moving into a new house.

Studying in Israel, Sienna interviewed Jews who had come there from other countries, uncovering traditions that had nearly disappeared.

“I was interviewing an elderly Jewish woman from an Iraqi Kurdish village,” he said. “She was married in the late 1920s, and I said, ‘Tell me about the henna at your wedding.’ ” To the surprise of her middle-aged daughter, the woman described a reverse technique using dough to create a negative image that is then laid over with henna.

“I was blown away,” Sienna said. “How many traditions have been lost because people haven’t recorded them?”

In Yemen, a similar technique used wax, he said, adding that Jewish Yemeni women told him: “Of course it hurts, and the pain that you feel when the wax goes on is just an introduction to the pain that you’ll feel every day of your life as a married woman.”

Although henna use declined as Israel modernized, in both Israel and the United States there is a renewed interest among young Jews, Sienna said.

“There is an increased hunger for ritual, for ceremony,” he said. “As they grow up today in multicultural America and attend Muslim or Indian weddings . . . here is something that both connects them to global consciousness but also ties them to tradition.”

As with many ancient traditions, henna art can evolve with the times: At the Eid celebration in Falls Church, after Azzar adorned the hand of a woman who had recently married in Morocco, she sprinkled colored glitter onto the wet design — a touch her mother never taught her.

As women sang songs about the bride and beat on a bendir drum, Saadia Haddou, 78, tottered over, supported by two younger women. She settled herself on a couch and showed off the deep auburn henna stains on her fingernails and toenails. Then she tugged her head scarf back to reveal a wavy mass of electric orange — the result of applying henna to white hair — and grinned.

“Henna brings happiness,” she said.