Wearing a pricey Italian suit, Paul Lorenc, a Park Avenue plastic surgeon, wields a purple pen, marking up faces, thighs, stomachs, and breasts to show patients where he’ll be cutting and what he’ll be removing; he injects wrinkle-smoothers like Botox and Restylane, and he removes post-operative stitches.

Dr. Lorenc’s uniform generally comprises a dark Canali suit, a bespoke, monogrammed white dress shirt, a silk Versace tie, gold cuff links from Tiffany & Co., and black leather shoes by Bally. Absent from his ensemble: a white lab coat.

In an effort to put their patients at ease — and, in some cases, to show off their fashion sense — many city doctors are hanging up their white jackets.

“It takes away that fear of being in a doctor’s office,” Dr. Lorenc, 51, said of his decision to not wear a lab coat. “It demystifies it, in a way. It makes you seem more approachable.” He said he rarely dons a lab coat, and that he wears a pair of hospital scrubs only during surgeries.

While the white jacket has long been considered a symbol of professionalism among health care practitioners, Dr. Lorenc said his suits “relay a certain aesthetic, and says that you care about taking care of yourself,” which he said is especially important when dealing with patients considering cosmetic surgery.

An Upper East Side pediatrician, Barry Stein, said he dresses to put his young patients at ease. He usually wears khakis and a polo shirt — and no coat. “The white coat looks very daunting, very formal, and makes them much more fearful,” Dr. Stein, 49, who teaches at Mount Sinai Hospital, said. “Very few pediatricians I know wear them even in the hospital. If a medical student doing a pediatric rotation, or an intern showed up in a white coat, and I was an attending physician, I’d tell them to leave it at home tomorrow.”

The white lab coat is so iconic that some patients — and not just the youngsters among them — associate the garment with ailments and malaise. This mental link can lead to “white coat hypertension” — a rise in blood pressure that occurs in a physician’s office.

In recent years, Dr. Stein said, it has become more acceptable for doctors of all stripes to forgo their lab coats. “The reality is: I never understood why anybody wears them,” he said. “The goal of them were, primarily, cleanliness, but it’s picking up the same germs as everything else you wear.”

The Occupational Safety and Health Administration does not regulate the use of lab coats and scrubs, which are considered “uniforms” that can be determined by the employer, an OSHA spokesman said.

“I don’t think it’s a hygiene issue, obviously,” an Upper East Side gynecologist, Isabel Blumberg, 35, said. “The only thing that’s messy is sonogram gel, and that’s water-based.”

Dr. Blumberg said the reason she doesn’t wear a lab coat is because she doesn’t want to cover up her designer attire. There’s an added benefit of Dr. Blumberg’s lab coat-free practice: It opens the line of communication between doctor and patient, she said. “It makes me seem less formal,” Dr. Blumberg, who on Thursday donned a blue-and-cream striped jacket by the designer Chloe, said. “It breaks down a barrier because it’s not like you’re wearing a uniform, and they aren’t. For me, that’s positive, and I’m able to talk to patients very freely. I don’t need to stand on ceremony and wear a white coat.”

Another gynecologist, Laura Corio, who practices on East 64th Street, said she’s not prepared to part ways with her white coat. “When I get to the office put on my lab coat, and begin working — it makes me feel like a doctor,” Dr. Corio, co-author of “The Change Before the Change,” about the years leading up to menopause, said. “It protects my clothing and, definitely, as a professional, I feel it’s important to look the part.”

While on rounds, a first-year dermatology resident at Mount Sinai Hospital, Achiamah Osei-Tutu, said she’s required to wear a white jacket. Whether that coat will be part of her post-residency attire will depend on her place of work, she said. “When in Rome, you do as the Romans do,” Dr. Osei-Tutu, 30, of Ditmas Park, said. “In an academic setting, it’s part and parcel of the presentation to wear a white coat.” In private practices, the dress codes can be a little more lenient, Dr. Osei-Tutu said, noting that her beneath-the-lab coat style is “classic with a lot of funky, on a resident’s salary.”

A patient interviewed after a recent doctor’s visit, Kevin Hamel, 28, said a lab coat does not a good doctor make. “I respect breaches of authority, disregard for the status quo, and non-conformity,” the Chelsea resident said. “So, doctors dressing like they are able to think for themselves would only increase my opinion of them, although the proof is in the pudding regarding their work.”

While wearing a white coat may no longer be standard operating procedure, the president of Ackley Uniforms, Jeffrey Singer, ventured that the knee-length, white jackets would win out in the lab coat-or-no debate. “Obviously, if you watch TV, every quack selling a product is in a lab coat,” Mr. Singer, who heads up an online lab coat retailer, said. “It’s marketing, but it’s also an icon to identify a doctor from some actor.”

That’s an important distinction, Mr. Singer, who said he has yet to see the back-and-forth impact on his business, said. “A seriously ill patient wants someone who looks professional — not goofy,” he said. “If you need a heart transplant, you’re not going to be impressed with a doctor wearing a propeller hat.”