Background With increasing cannabis use, physicians need to know more about its respiratory effects. However, there are few long term studies of cannabis smoking, mostly due to legality issues and the confounding effects of tobacco.

Aims We reviewed the effect of chronic cannabis use on bullous lung disease.

Methods 18 out of 69 English-language publications, prior to April 2016, from MEDLINE, Scopus, and Web of Science databases, which reported bullous lung disease in cannabis users, were examined. Case reports and case series were included.

Results The only cross-sectional study reported an increase in the rates of macroscopic emphysema in tobacco only (17 of 92) and tobacco + cannabis smokers (15 of 91), but not in cannabis only smokers (1 of 75) compared to non-smokers.1

The remaining case series and case reports described a total of 56 marijuana smokers presenting with bullous lung disease, often with pneumothorax and predominantly upper lobe involvement (Table 1). Concurrent tobacco smoking was present in all but 3 cases. The majority of cases reported heavy cannabis use, though direct comparison was difficult due to variation in usage measurements. All 4 case series that measured lung function reported normal findings.

Conclusions While the clinical association of cannabis smoking and peripheral lung bullae is well recognised (and consequently often not reported) there is scant documentation in the literature correlating marijuana smoking with bullous lung disease.

Reference

1. Aldington S, et al. Effect of cannabis on pulmonary structure, function and symptoms. Thorax. 2007;62(12):1058–63.