A healthy young man presented to the emergency department with mild hemoptysis associated with cannabis abuse. He was on no medications and cocaine abuse was ruled out by both history and negative toxicology screens. There were neither signs of an infection, nor of a systemic or cardiac disease. Imaging studies were consistent with diffuse alveolar hemorrhage, a reported, albeit rare adverse drug reaction of tetrahydrocannabinol (Naranjo score 6). The patient improved spontaneously within a few days, hemoptysis stopped and repeat imaging was entirely normal.

With the increase in cannabis abuse and enhanced cannabis potency worldwide clinicians may increasingly encounter even unusual cannabis-associated adverse drug reactions, including associated diffuse alveolar hemorrhage.