ABSTRACT
Objective@#This case report was intended to report on a rare cause of spontaneous pneumomediastinum (SPM). @*Methods@#When a patient with Crohn's disease (CD) visited our hospital for pneumomediastinum, a disease activity evaluation was performed, and specific questions were asked to identify possible causes of SPM. @*Results@#The disease status of CD was confirmed as in active by evaluation. Specific questions about situations requiring the Valsalva maneuver, including vigorous exercise, lifting heavy objects, and difficult stool passage, were asked, but none were applicable. When asked an open question regarding incidents related to deep breathing, the patient answered that he had recently started smoking an electronic cigarette which required taking deep breaths. @*Conclusion@#Even when there is an underlying disease, specific history-taking is important if the possibility of complications related to the underlying disease is low. A new wave of previously unseen complications has emerged in parallel with increased electronic cigarette use.