RALEIGH, N.C. — The death of a woman who apparently overdosed on skin-numbing cream has doctors who perform laser hair surgery re-thinking their own policies.

Dermatologist William Ketcham said he always re-evaluates safety procedures in his Cary and Garner offices.

"There's only one difference between a medicine and a poison and that's dosage," Ketcham said.

When 22-year-old Shiri Berg died last month apparently from a numbing cream overdose prior to hair removal at Premier Body Laser Clinics, it was a wake-up call for many doctors.

"It's absolutely stunning. Theoretically, you know you can get absorption of Lidocaine to potentially toxic levels. To have it actually happen is harrowing to even think about," Ketcham said.

On a rare occasion, Ketcham uses 4 percent over-the-counter Lidocaine in his office. Berg's attorney said she was given compounded Lidocaine from Premier Body Laser Clinics with a strength of 10 percent.

WRAL has learned that it is common practice for people who use numbing cream to cover the area with plastic wrap to help it sink in. Doctors say it is very dangerous because it makes the cream more the toxic. Berg's attorney claims Premier told its clients to do that, but it is not known whether Berg did that.

Ketcham believes a growing number of laser procedures thought of as "cosmetic" are being handled by non-medical people. He calls it a dangerous trend.

"There has to be a physician involved. There's no doubt in my mind about that. The definition of physician involvement is where the rubber meets the road," Ketcham said.

Ketcham believes a doctor needs to be in the building when any laser treatment is done. Premier's attorney said he cannot comment about the plastic wrap allegation because the investigation into Berg's death is ongoing.