Up in smoke: An unusual case of diffuse alveolar hemorrhage from marijuana

Diffuse alveolar hemorrhage (DAH) can be a serious and life threating condition. Illicit substance use has been associated with DAH, with cocaine being the most widely reported. Marijuana use has been associated with pulmonary complications in the form of pneumomediatsium, pneumothorax, bullous disease, and pulmonary aspergillosis. We present a case of diffuse alveolar hemorrhage (DAH) resulting from marijuana inhalation, a finding rarely described in the literature. A 21-year-old male presented with several episodes of hemoptysis after drinking alcohol and smoking marijuana. He reported smoking 5-8 joints per day of marijuana (he denied use of bongs or other inhalant aids). His respiratory exam revealed bilateral fine rales. Laboratory evaluation included leukocytosis with left shift, normal platelets, coagulation profile, and a urine toxicology screen positive for tetrahydocanabinoid (THC). Chest CT revealed bilateral diffuse alveolar infiltrates suggestive of DAH. A bronchoscopy with BAL of bilateral upper lobes consistent with DAH with negative microbiologic studies, hemosiderin laden macrophages were present. Additional workup included a normal Echocardiogram, negative autoimmune serologies. His hemoptysis resolved with supportive care. DAH is a potentially fatal disease that has been associated with illicit substance use, most commonly cocaine. Recently, reports have surfaced associating marijuana use with DAH, though these cases have all involved the use of bongs or other inhalant aids, leading to the hypothesis that combustibles and inhaled particles may be the etiologic factor. This is the second report of DAH developing after smoking only marijuana, though the etiology for the association between marijuana use and DAH remains uncertain.