With the increasing prevalence of cannabis use, more people than ever are suffering allergic reactions to marijuana. For some, these allergies can prove to be life-threatening, sending them into anaphylactic shock like people with severe peanut allergies.

Doneil Oliphant learned first hand about his own allergy when he touched his face after handling cannabis oil. “My eyes were swollen (almost) completely shut. You could barely recognize me,” Oliphant told CTV News. “I didn’t even know it was possible.”

Dr. Gordon Sussman, the allergist and immunologist who treated Oliphant, says this issue isn’t receiving enough attention. So he's launched the first Canadian study that will try to find out just how many people are living with undiagnosed cannabis allergies.

“If you look at a study done out of Colorado, about 10 per cent of people just with passive exposure [to marijuana] did have sensitization or allergy symptoms,” he said. “At this point, it’s under-recognized and under-diagnosed.”

“Skin symptoms are generally from touching it," Sussman explained. "You can sometimes see itchy skin and hives and you can sometimes see swelling of the eye if you touch your eye after touching the marijuana plant. Respiratory symptoms can be nasal running and sneezing with associated itchy, watery eyes. Occasionally you’ll see wheezing, shortness of breath and asthmatic reactions. Anaphylactic symptoms generally occur with hempseed [or eating marijuana products].”

"Potentially, any anaphylactic event can be serious and life-threatening," Sussman added.

An Ontario Provincial Police Officer, who asked to stay anonymous, has claimed that her allergies have had an affect on both her career and social life. She first discovered her allergy when she was involved with a marijuana seizure.

“We were doing drug eradication, so we were pulling marijuana plants from a field. I had a reaction to the plants which I’d never had before and my hands and forearms swelled and I got a really bad rash on them and really bad swelling,” she recalled. “I wound up having to go to (an emergency room) because the swelling and the rash was so bad that I actually couldn’t use my hands.”

She now carries an EpiPen, and even contact with second hand smoke can cause intense pain for her. Of the impact it has had on her life she says, “I’m not able to go to concerts. And once it’s legalized, I’m afraid [of] even just walking down the street.”