Occupational asthma is a disease where the pathophysiological characteristics of asthma are linked to repeated exposure to a sensitizing agent present in the workspace. Assessment of patients with severe asthma to identify and manage comorbidities improves asthma control and is recommended in international guidelines on the management of severe asthma. We report the case of a 49-year-old patient, nonsmoker, without atopy, who had severe work-related asthma due to exposure to isocyanates, which was uncontrolled despite the avoidance of the occupational exposure and maximal medical treatment. A systematic assessment for possible comorbidities revealed gastroesophageal reflux and obstructive sleep apnea syndrome. The specific management of these two comorbidities led to an improvement of asthma control with a reduction in the number of exacerbations, a reduced burden of treatment and a resumption of employment. As with all cases of severe asthma, the assessment of comorbidities must be systematic in the presence of an occupational asthma which persists after the cessation of the occupational exposure. The management of these comorbidities can lead to an improvement in asthma control and severity. Copyright © 2019 SPLF. Published by Elsevier Masson SAS. All rights reserved.