I'm allergic to pot. One secondhand whiff of somebody else's joint and my nose clogs up. I get a headache and I start to itch. And if I'm around enough of it—say at a concert or something—I'm sick the whole weekend, coughing and weak in bed.
I'm lucky. Immunologist Dr. Purvi Parikh with Allergy Asthma Associates of Murray Hill in New York says cold-like symptoms are on the milder end of marijuana allergy reactions. "Some people get full blown asthma attacks, rashes, and even anaphylaxis." To clarify, "anaphylaxis" means anaphylactic shock—as in shutting down your organs, as in death. Now that weed is increasingly decriminalized and ubiquitous, this makes for a whole new issue.
While death by pot isn't exactly common, allergies to it are. Scientists have known since the 1930s that if you're allergic to pollen or mold, you're likely allergic to marijuana. Back then, 22 percent of allergy sufferers also got sick around pot. But according to separate studies from 2000 and 2015, that number's now 70-73 percent. An estimated 40-50 million Americans have seasonal allergies so—with a little math—as many as 36.5 million may be allergic to pot.
"People who already have seasonal allergies are more at risk because marijuana is a type of plant as well," Parikh says. "Allergies have both a genetic as well as environmental component. Someone who is never exposed to pot will likely not develop a pot allergy. But as exposure gets more and more, that also increases your risk."
As many as 36.5 million Americans may be allergic to pot.
This "exposure" comes from first or secondhand smoke. For people like me, decriminalization has been a nightmare. I've had to leave restaurants because my waiter lit up during his break, and I missed the Women's March in DC because DCMJ—a District of Columbia marijuana advocacy group—led a public smoke-in that weekend.
"I had one patient—she doesn't even smoke but her neighbors were and it was coming in through her heating duct," Parikh says. "[E]very time they would smoke marijuana, she would go into an asthma attack...I've had people move, actually, quite frequently because of their allergy."
In addition to working as a practicing allergist and immunologist, Parikh also teaches at the New York University (NYU) School of Medicine and is national spokeswoman for the Allergy and Asthma Network, a non-profit patient advocacy group. She compares marijuana allergies to health concerns from secondhand cigarette smoke: A side effect that happens when you make decisions that impact what others around you breathe. "I do see it moving in the same direction as the tobacco industry in that certain places may have to become completely smoke-free."
But marijuana advocates don't want to hear it. "[O]ur position is no one is making you take it," says Adam Eidinger, cofounder of DCMJ. When I told Eidinger this was the same positioning the tobacco industry took after secondhand smoke's effects were first known, he said: "Wow, that's spin, cause [sic] it's not tobacco."
Marijuana isn't tobacco. But clean air is clean air, which is why Parikh says joint smoke can cause emphysema and COPD, just like cigarettes. Lung disease is a separate medical reaction than one from an allergy, she explains, so "when someone develops an allergy to [marijuana], it's twice as deadly if you inhale it." While I'm one of the lucky ones who won't go into anaphylactic shock if you light up in public, on behalf of those who will and 36.5 million others, I'd kindly ask you not to.
But neither I, nor science, can convince Eidinger. "I actually have never met a person who can prove they are allergic to cannabis," Eidinger told me over direct message.
To "prove" allergies, though, most doctors rely on prick tests. Oils from a plant go under a patient's skin; physicians monitor reaction. "Many allergists are using either marijuana oil or hemp oil if there's a strong clinical suspicion that someone is allergic," Parikh explains.
Unfortunately—even with proof—it took cigarette smokers decades to acknowledge how their decisions impacted the health of others. Having spent my entire adult life dealing with deniers like Eidinger, I asked Parikh how she responds to those who claim marijuana allergies aren't real.
"They're mistaken," she answers immediately, "because they are very real and we have published studies now that prove it...Probably we'll be seeing more and more of it as more states legalize marijuana and as the industry grows in the US."