A survey in the US has shown that cannabis users are often asthmatic, and some have allergies from cannabis smoking or its second-hand smoke.
Cannabis allergies can potentially cause respiratory symptoms, contact urticaria, angioedema, and uncommonly anaphylaxis. Inhalation of cannabis may also manifest in allergic rhinitis, conjunctivitis, wheezing, and throat oedema. Given the widespread legal use of cannabis, more information is needed on the effects of cannabis use, particularly smoking, on individuals with asthma and allergies.
The anonymous survey, conducted in concert with the Allergy & Asthma Network, consisted of 489 participants, 18% of whom reported cannabis use. A surprising 60% were asthmatic, and 40% had uncontrolled asthma.
Inhalation routes were the most popular way of taking cannabis. About half of users smoked cannabis, while a third vaped it. Only 40% reported being asked by their physician about cannabis use, and about the same proportion of participants were willing to talk to a physician about their cannabis use, said study co-author and cannabis allergy expert, William Silvers, MD.
“In order to more completely manage their allergy/asthma patients, allergists should increase their knowledge about cannabis and inquire about cannabis use including types of cannabinoid, route of use, reasons for use, and adverse effects,” said Dr Silvers. “As with cigarette smoking, efforts should be made to reduce smoking of cannabis, and recommend other potentially safer routes such as edibles and sublingual tinctures.”
Reported positive effects of cannabis use (eg, reduced pain, calm, improved sleep) were more frequent than adverse effects (eg, cough, increased appetite, anxiety). Approximately 20% of survey respondents reported coughing from cannabis, which was associated with smoking cannabis; this was cause for concern as it may indicate smoking risks for cannabis users.
“It surprised me that over half of the cannabis users in this study who have asthma were smoking it,” said principal investigator Joanna Zeiger, PhD. “And further, of those with uncontrolled asthma, half reported smoking cannabis. We also found that people with asthma are not routinely being asked or advised by their physician about cannabis and how they are consuming it.”
The researchers commented that further research into the relationship of cannabis and allergies is warranted.
“We look forward to future studies of larger, more diverse cohorts to better explore more deeply the effect of cannabis use on asthma and other allergic disorders,” said Dr Zeiger.
Source: News-Medical.Net
Journal information: Zeiger, J. S., et al. (2021) Cannabis attitudes and patterns of use among followers of the Allergy & Asthma Network. Annals of Allergy, Asthma & Immunology.doi.org/10.1016/j.anai.2021.01.014.
