The allergist has become one of the greatest buzz kills in our society. Many beer and bread lovers have had their hearts broken by doctors delivering them a diagnosis of gluten sensitivity. Cheese and ice cream fanatics have sobbed tears over lactose intolerance sentences. And you can only imagine what goes through a die hard pothead’s mind on the day a doctor tells them that they’re allergic to cannabis.

Imagine, or ask Conor Purdon, the medical marijuana patient and dispensary owner who recently got some of the worst news a stoner can get from a doctor. After ten years of marijuana use, at the age of 25, the Toronto resident has developed an allergy to his beloved sensimilla.

Purdon knew something was up last February while in the midst of a dab. “I actually took a hit of what we call concentrate,” he told CBC News. “I hit one of those, and I’m not sure if I rubbed something in my eye, or what happened, but I had a heavy kind of allergy reaction to my face.”

Red eyes are nothing new for fans of the dab, but what this stoner experienced was a different level of cheeched optics. “Next day I woke up, it really hadn’t gone away… swelling in my eyes, really, really, red.” He knew that he had a cannabis allergy. “It was a sad moment,” he said.

What’s worse, some researchers claim that weed allergies are becoming more and more common. “For about a decade, IgE-mediated cannabis (marihuana) allergy seems to be on the rise,” reads a European study published last year. “The clinical manifestations of a cannabis allergy can vary from mild to life-threatening reactions,” the study warns.

Dang it. The list of ailments cannabis has been shown to treat grows every year, but now there’s at least one that weed causes (oh yeah, and this one too).

Though cannabis allergy is rare, it can be serious, or at least annoying, business. “The symptoms are generally due to inhaling marijuana or touching marijuana,” Dr. Gordon Sussman told CBC. “So if you inhale the marijuana, you can have a running [nose] and sneezing and itchy watery eyes and coughing, wheezing and shortness of breath. If you touch marijuana you can have hives and swelling.” That last part is a concern especially for cultivators and other workers in the cannabis industry.

Allergy to marijuana is probably under-reported for a variety of reasons. Those who experience reactions when they’re underage or in a 420-unfriendly state aren’t likely to tell their doctors. And since it’s not a widely known phenomenon, many who suffer from it probably don’t know what it is they’re suffering from. But Sussman says it’s important for users who think they’ve had a reaction to seek medical attention, both for their own sake and so that the allergy can be better understood by doctors, those damn debby downer doctors.