Bronchial Challenge in the Diagnosis of Cannabis Allergy.

We have read with great interest the recent review published by Dr. Ebo and collaborators on cannabis allergy. It highlights the difficulties in getting a valid diagnosis because some patients do not admit its consumption, which may not be legalized, there are no commercial extracts and there are problems in cutaneous tests interpretation due to cross-reactivity with other related allergens. In addition to this, bronchial challenge is considered the confirmatory diagnosis, but it is complex to perform. This also occurs in diagnosis of occupational asthma, such as in baker's asthma, in which we have investigated a reliable marker to avoid the bronchial challenge. However, we think it is necessary to do this test to ensure a correct etiological diagnosis of cannabis asthma, and we have carried out bronchial challenge with cannabis on more than 600 patients since 2009, all them active consumers. In our country cannabis consumption has not been legalized, but to do this challenges we asked the National Court for permission, which we obtained easily. Although molecular diagnosis has helped in revealing the problems caused by cross-reactivity, the gold standard continues to be the provocation. In our articles we detail how to do it safely, and we encourage our colleagues to reach a definitive diagnosis that cannabis is the cause of their bronchial symptoms.