Yahoo! News: Can you be allergic to marijuana?

By Anna Medaris Miller 

March 23, 2015 1:47 PM

About seven years ago, Kathryn Wick was going about her job as a child crimes detective in Texas when she entered a house that literally took her breath away. "It felt like my throat was just like shut completely off -- I couldn't breathe," says Wick, 30. She left the scene and went to a hospital, where she was treated with two EpiPens and a hefty dose of the severe allergy medication Prednisone. "I come to find out," Wick says, "they found a whole bunch of marijuana in the house." Still, she brushed her reaction off as a fluke and went back to work. 

Then it happened again -- this time, at a house on the other side of the county. "As soon as I entered the door, I was done," Wick says. After that, any time she was around pot or even near anyone who had been around it, she lost her breath and felt so itchy she'd scratch her neck until it bled. "I'd blow up like a red balloon, and my throat would swell," Wick says. 

By then, Wick knew it wasn't a fluke: She was allergic to marijuana. 

"They say it helps with glaucoma, it helps with cancer patients -- and I'm so thrilled that it does that," says Wick, who now works in a hospital. "But I'm sitting over here in the corner saying, 'What about me?'" 

'A New Challenge' 

Researchers don't know how many people are allergic to marijuana, but reports of reactions -- which range from sneezing and rashes to anaphylaxis -- to both marijuana exposure and use are on the rise, according to a paper published this month in the Annals of Allergy, Asthma & Immunology. 

"It wasn't necessarily a surprise that a pollinating plant could cause allergies," says paper co-author Thad Ocampo, an allergist at Wilford Hall Ambulatory Surgical Center in San Antonio, Texas, an Air Force medical treatment facility. "But I was surprised by the variety of allergic conditions that have been attributed to cannabis use and exposure." 

Anecdotally, allergists have seen more patients with the allergy in their clinics, too. Dr. William Silvers, an allergist in Englewood, Colorado, and clinical professor of medicine at the University of Colorado School of Medicine, has seen two patients in the past year with the allergy. That's about the same number of patients he's seen with it in his last 30 years of practice. 

"With increasing exposure given the availability of marijuana, my guess is there will be increasing sensitization, especially [with] patients who have other allergies, and we will be seeing more," Silvers says. "This is a new challenge for the allergy community." 

It's unclear what the exact allergens are -- be it the pollen, THC (the main ingredient of cannabis that alters brain function) or another compound of the marijuana plant Cannabis sativa, the Annals paper says. In all likelihood, people react to different compounds or combinations of compounds, says Dr. James Sublett, an allergist-immunologist and president of the American College of Allergy, Asthma & Immunology. "A lot of people think of an allergen as just the pollen grain, but actually, it's at the biochemical level," he says. 

Marijuana's illegal status in many states, including Texas, only complicates matters by making the allergy difficult to study, identify and treat. On the flip side, more widespread marijuana production and use in the places where it is legal -- and even where it's not -- is a nightmare for people like Wick, who have to go to greater lengths to avoid exposure. 

"If it becomes legal in Texas," she says, "I'll have to be sitting at home on disability to stay alive." 

Life in a Bubble

After pinpointing the cause of her reactions, Wick sought help from an allergist. But when she called around and told the clinics what she was allergic to, "I got laughed at," she says. It took her more than a dozen tries before she found Dr. David Engler, an allergist at the Houston Allergy and Asthma Clinic, who agreed to see her. "He said, 'I don't make fun of anybody's allergies because you never know when it's real,'" Wick remembers. "'And yours is real.'" 

Still, confirming her allergy with a skin test -- a common way to diagnose other allergies -- isn't always possible, particularly in places like Texas where the substance is illegal. Engler says the U.S. Drug Enforcement Administration denied his office's request for a small sample of cannabis extract that would be used to test for Wick's allergy, then destroyed. There's also no blood test commercially available, he says. 

So in Wick's and other patients' cases, the allergy is often identified simply by taking a thorough clinical history. "By history, her diagnosis is so certain, and it's not really going to change my treatment," Engler says.

Like with any allergy, the best way to treat a marijuana allergy is to avoid it. For people who only react to smoking or ingesting the substance, that sounds easy -- not to mention, always legal. But for people like one of Silvers' patients, who developed a skin reaction after working in a marijuana cultivation facility, avoiding the allergen could mean being out of a job. "The more exposure, the worse the allergic reaction," Silvers says. 

Then there's the rarer, more severe cases like Wick's. For her, avoiding people who have recently smoked, places where people have lit up or even air that carries the plant's pollen is simply not practical. "It's a daily struggle," Wick says. "That's the hardest part -- trying to live in a little bubble." 

What's more, unlike some other allergies, a marijuana allergy can't yet be treated through desensitization -- a process of exposing patients to allergens to lessen their reactions -- since there's no cannabis extract commercially available. 

So for Wick, treatment comes down to being prepared. When she goes grocery shopping, she's in and out of the store by 8:30 a.m., when other shoppers start to flood in. When she travels -- which is rarely -- she packs a kit filled with EpiPens, Benadryl and steroids. She used to love to go out dancing, but she doesn't do that anymore. She taught her two daughters, ages 6 and 12, how to inject her with an EpiPen. She's canceled plans to visit Colorado and the District of Columbia. And most days, she only travels between home and work, where she wears nylon sleeves under her uniform. 

Wick also tries to take three shots of an asthma medication every two weeks. The medication helps her throat stay open in the case of a reaction. "I may be scratching blood off my neck, but I can breathe," Wick says. "If I can breathe, I'm good." 

Still, Wick can't always take the shots. Her tab is about $500 a month after insurance and the medication company chip in. (While insurance companies don't recognize marijuana allergies, they do acknowledge asthma, which Wick also has.) 

Despite her medication lapses, Wick's bigger concern is that her children will develop the allergy, too. "I hear all the time that people wish their kids were allergic to weed, and I tell them, no they don't," she says. "Hopefully by the time [my children] grow up, there will be some kind of cure."