Growing up, your parents and teachers may have been told all kinds of reasons not to smoke pot.
But what you may not have heard is that marijuana — like other pollen-bearing plants — can cause allergies, including hay fever.
Marijuana: The allergen you never knew existed
“In Cannabis Sativa: The Unconventional ‘Weed’ Allergen,” published in the Annals of Allergy, Asthma and Immunology, the scientific publication of the American College of Allergy, Asthma and Immunology (ACAAI), summarized research on the ways cannabis can act as an allergen.
There are various allergic responses that may be unfamiliar to marijuana users. Included in the article is information on case reports regarding episodes of allergic reactions, hypersensitivity and even anaphylaxis (a severe allergic reaction) to cannabis in its various forms.
Among other things, cannabis pollen or cannabis smoke exposure has resulted in symptoms of allergic rhinitis (hay fever) conjunctivitis and asthma. Allergic asthma triggered by seasonal and occupational exposure to cannabis has also been reported. For instance, a 2013 study noted that workers involved in processing hemp fibers at a textile mill had significantly higher prevalence of chronic respiratory symptoms, and sensitization of laboratory workers who handled and tested marijuana has also been reported.
The article notes that although pot has been used for five millennia for spiritual, medicinal, and recreational use — and even routinely by American physicians in the late 19th century — marijuana was first prohibited in the United States under the 1937 Marihuana Tax Act. More restrictions were put in place in 1970, when the federal government passed the Controlled Substances Abuse Act classifying marijuana as a Schedule I substance.
The authors of the article point out that cannabis’ legal status may create barriers for accurate and clear patient reporting, and that legal limitations may pose diagnostic challenges. As with other allergens, however, they say that avoidance is recommended, but that your doctor might tell you that antihistamines, intranasal steroids and nasal decongestants can be used to treat symptoms of pot-induced hay fever.