French researchers are calling into question the safety of a cosmetic procedure that offers to melt away fat without surgery, exercise or pills.

The doctors, writing in the journal Clinical Infectious Diseases, warn that the procedure, known as mesotherapy, can also leave patients with particularly hard-to-treat and potentially disfiguring bacterial infections.

Mesotherapy involves the injection of a reportedly fat-dissolving solution into unwanted fat deposits. Over weeks or months, the broken down fat disappears as it is absorbed by the body.

Dr. Stéphanie Regnier, of the Infectious Disease Unit of Pitié-Salpetrière Hospital in Paris and colleagues from another Paris hospital, detail the cases of 16 mesotherapy patients who developed painful, inflamed, oozing infections of the skin.

It’s hard to determine how often such infections occur following mesotherapy, the authors note; all 16 patients had been treated by the same doctor at a Paris clinic, now closed, between October 2006 and January 2007. Most of them had received multiple courses of mesotherapy.

The infections were treated by the research institutions with surgery, drainage of abscesses, and, in most cases, antibiotics. Patients were followed until they were infection-free for 6 months.

The researchers were alarmed at how difficult the infections proved to treat even when combination antibiotics were used.

“Not only did antibiotics not help to cure these patients, but more surprisingly, antibiotics did not prevent the appearance of new lesions in this group,” they wrote about 7 of 14 patients.

They concluded surgery may still be the best way to treat such skin infections, and “the rationale behind the use of antibiotics…should be questioned.”

In an accompanying editorial, Drs. Jaap T. van Dissel and Ed J. Kuijper of Leiden University Medical Center in The Netherlands said more study is “urgently needed.” They concluded that physicians should suspect infections if patients develop similar symptoms after any kind of cosmetic skin procedure.

“Likely, many cases go undetected,” van Dissel told Reuters Health in an email.

Dr. Adam Rotunda, a dermatologist who performs mesotherapy clinical trials at UCLA’s David Geffen School of Medicine, told Reuters Health he would like to see some oversight because currently there are no standards of practice established in the United States.

“The field attracts a rogue element because there’s no FDA approval of the injected compounds,” he said in a telephone interview. “It’s buyer beware for consumers. The risks, at this point, are still unknown,” he added.

And Baltimore dermatologist Dr. Robert Weiss, former past president of the American Society of Dermatologic Surgery, says he hasn’t seen clinical proof that mesotherapy works as advertised.

“I do a lot of laser lipolysis (dissolving of fat) and maybe 1 out of 5 patients I see, they’ve already tried mesotherapy because they were interested in reducing their fat and it did nothing other than get painful, tender, lumpy, and stay lumpy,” he told Reuters Health.

SOURCE: Journal of Clinical Infectious Diseases, November 1, 2009.