Sneezing, wheezing, itching and breaking out in hives: It’s precisely the opposite of what you signed up for when the joint made its way around to you. While almost everyone has experienced the odd coughing fit or “green out,” experts say the number of people who will experience an allergic reaction will rise as Canada’s legal pot market takes root and more people partake.
Cannabis allergies and symptoms
“Cannabis sativa is a weed, and the pollen can cause allergies just like other weed pollen, tree or grass pollen,” says allergist-immunologist Dr. William Silvers. Practising in Colorado, the first U.S. state to legalize recreational cannabis (alongside Washington), Silvers sees his share of unpleasant reactions.
The symptoms aren’t usually a far cry from more common plant allergies like flowers and grass. But since sufferers of most allergies don’t attempt to smoke, vape or eat the source of their misery, the effects can be more pronounced. Often, the allergy doesn’t have to be specific to cannabis for said weed to cause a negative reaction.
“People who have an allergic background and have exposure to cannabis may have allergic reactions,” Silvers says. “Even those that may not have had allergies before, especially if they are in close contact with it.”
Research suggests sensitivity to hemp seeds (high-nutrient seeds from the plant itself) can also trigger an allergic response.
How common are cannabis allergies?
According to Silvers, there’s no clinical figure yet on how many people are sensitive to cannabis. While standard skin testing can determine if a pot allergy is contact-based, consumers will have to abide a period of trial and error that he says will show more evidence of sensitivity than previously assumed.
Cannabis workers, Silvers mentions, are at special risk of finding themselves itchy and uncomfortable due to prolonged contact with the plant during its many stages of growth.
“People on the growing and cultivation side have experienced classic allergies such as allergic rhinitis (sneezy, stuffy nose), conjunctivitis (itchy eyes), and asthma (wheezing, coughing),” he says. “Skin reactions like hives and dermatitis are also seen with close contact with weed.”
As cases of extreme sensitivity and anaphylactic shock are incredibly rare, others in the medical community are confident consumers will figure it out without much trouble.
“Few people are going to have it severely enough to pursue diagnosis,” explains Dr. Jordan Tishler, a physician and cannabis therapeutics specialist based in Massachusetts. “Most will either just stop the cannabis in a process of elimination, or just live with it.”
Tishler adds that since cannabis allergies can resemble any number of allergic reactions, it’s possible some users could mistake simple hay fever for something more nefarious.
“Given that many people have allergies in a seasonal fashion, it may be hard to pin it on the cannabis.” In either case, he suggests taking standard allergy medications if symptoms are on the mild side. There’s also the possibility that some of what’s ingested (usually when smoked) could contain traces of mold; offering another explanation for those watery eyes and sore lungs.
Does consumption method matter?
While what research is available doesn’t suggest that any one method of consuming cannabis is more or less likely to provoke an allergic reaction, Tishler isn’t sure such a distinction is necessary.
“I think the method of ingestion is unlikely to make a difference,” he says. Silvers emphasizes that while no mode of consumption is more dangerous in a general sense, the nature of a person’s allergy will often dictate how they react to an allergen.
For instance, smoking weed would cause respiratory reactions, while an edible or canna-infused drink could cause cramping, vomiting or the dreaded anaphylaxis – as it did in one study. Life-threatening reactions to second-hand pot smoke are almost non-existent, with the only reported case being that of a six-year-old with severe asthma.
How to treat a cannabis allergy
Silvers says that for the few who know they have it, recourse is pretty slim. Even if cannabis is more than a mild allergen, the best course of action is aversion.
“Avoid the source. If you’re exposed [to cannabis], treat with medicines like antihistamines and inhaled steroids, some of which may need to be prescribed by a physician.”
He says given pot’s legal status, more physicians are up to speed on the plant and open to discussion than in years past – so don’t be afraid to spark up a conversation with your doctor if your cannabis has you hitting the Benadryl harder than the pipe.