[Hemoptysis in a young man smoking cannabis].

The respiratory toxicity of cannabis is well known today. Along with the classic cannabis 'joint', there are other ways of consuming it, which should be known. Smoking cannabis that has been cut with micro-particles of silicon dioxide may cause hemoptysis. We will describe here the case of a young 16-year-old man who was in the hospital because of hemoptic expectoration. The etiologic investigation was negative, in particular a thoracic scan and a bronchial fiberscope. Questioning the patient afterwards allowed us to discover the inhalation of cannabis 2 h before the hemoptysis, cannabis mixed with micro-particles of silicon dioxide. Stopping inhalation stopped the symptoms. Pediatricians should be familiarized with such practices. Silicon dioxide particles cause ENT problems or bronchial ones (coughing, spitting, hemoptysis, wheezing). Over the long term, the risk of silicosis cannot be excluded, although a longer and more complete exposure is necessary.