What You Need To Know About Cannabis Allergy

As more states are legalizing recreational and medical cannabis across the United States, the cannabis market is growing.

But as more people consume cannabis, potential adverse events to the plant are becoming evident, including cannabis allergy.

What Is Cannabis Allergy?

Some cannabis consumers may suffer from a cannabis allergy, which is a body reaction to the cannabis plant. It has recently become relevant because of recent legalization in the U.S. and Canada.

Although the study on cannabis allergy is still in its infancy, we can outline its most relevant characteristics.

Cannabis sensitization is not so rare. Humans can be allergic to almost anything, and it is even possible to have multiple allergies. People may be exposed to hempseed hidden in foods and drinks. However, they may also suffer from sensitization by inhaling, smoking, touching, and eating cannabis.

Dr. Gordon L. Sussman is an allergist and professor of medicine at the University of Toronto, Canada. He explained that symptoms of cannabis allergy include cutaneous or skin symptoms, including hives.

Regarding occupational exposure, a study has shown a high prevalence of work-related allergic symptoms in the employees of one indoor cannabis grow facility in Seattle, WA. Another study has found that the origins of the respiratory and cutaneous symptoms during cannabis exposure reported remain elusive, probably because of non-immune reactions.

Dr. Sussman explained that some people may experience severe anaphylactic, multisystem allergic reactions, and cross-reactivity with food due to ingestion of hempseed.

Diagnosis

There is no standardized test to diagnose cannabis allergy nowadays. However, clinical history is the cornerstone of its diagnosis. Dr. Sussman explained people should do prick skin testing with homemade allergy extracts to confirm the allergy.

A skin prick test, also known as a puncture or scratch test, checks for immediate allergic reactions to over 50 substances at once. People do this test to identify allergies to pollen, mold, pet dander, dust mites, and foods. “The cannabis skin test is made by extracting buds and leaves in 5ml of saline, and retested by a standard prick test, which is very safe,” Dr. Sussman said.

But even blood testing for allergy antibodies is also becoming available. “A couple of labs in the U.S. developed blood tests. Blood specimen will be sent to the lab as we are now developing research studies to look at this further,” he said.

People may also may develop allergies to selective cannabis strains. In a case report published in the Allergy, Asthma & Clinical Immunology journal, a 31-year-old male patient suffered from several episodes of localized pruritus and erythema after direct contact with various strains of cannabis. He developed a severe swelling around the eyes (bilateral periorbital edema) shortly after coming into direct contact with one particular strain. However, he didn’t refer to any adverse symptoms when smoking cannabis. The study concluded that this was the first reported case of selective cannabis strain allergy. The patient had positive testing to three of five strains, and he appeared to be more sensitized to Sativa dominant strains.

Passive Exposure To Cannabis

As we have seen, cannabis allergy can also occur when be exposed to given strains. But studies have also reported cases related to passive exposure to cannabis. Researchers have not a clear understanding of the effects of passive exposure to cannabis smoke as a potential route of allergic sensitization.

A study reported a case of a 5-year-old boy suffering from cannabis-related allergies via passive exposure to airborne cannabis allergen. Other people reported cannabis sensitization and allergy because of passive exposure to cannabis smoke and (or) indirect cutaneous transmission.

Cannabis Legalization And Cannabis Allergy

Researchers still know little about cannabis allergy. However, cases studies and trials are giving more information to understand more about how it works. It is likely to become common as more states are legalizing cannabis.

“We see increases in numbers of cases. Recognition and testing are part of this. Also, legalization would lead to increase exposure and sensitization,” Dr. Sussman said.

In 2019, the estimated number of cannabis consumers in the United States was 40.3 million people. By 2025, the number of cannabis consumers is expected to reach 46.6 million people, according to Statista.