Scientists have discovered cannabis is an allergen.
A new study published in the Annals of Allergy, Asthma and Immunology says cannabis, like other pollen-bearing plants, can provoke allergic reactions.
The research, led by Dr Thad Ocampo, concluded that while episodes of cannabis allergies were "relatively uncommon", they had been "reported with increased" frequency. They say marijuana use has led to symptoms including hay fever, conjunctivitis, asthma and even anaphylaxis. Because cannabis is still mostly illegal in the US, there are no concrete figures on how common allergies are.
"Much research is still needed to more definitively define pertinent allergens, develop a standardised extract, establish diagnostic sensitivity and specificity, and clarify treatment options for clinically affected Cannabis-allergic patients," the study concludes.