Severe airflow obstruction in a patient with ulcerative colitis and toxic epidermal necrolysis: A case report

Bronchiolitis is a rare condition mainly affecting the intralobular conducting and transitional small airways. The present study describes a case of severe airflow limitation in a patient with ulcerative colitis who developed toxic epidermal necrolysis following mesalazine therapy. Forced expiratory volume in one second was decreased and a flow-volume curve showed airflow limitation, but the single-breath diffusing capacity of the lung for carbon monoxide (DL CO ) and DL CO divided by alveolar volume (DL CO /VA) were not decreased. This rare clinical condition should be considered as a differential diagnosis for subjects presenting with sub-acutely developed airflow obstruction if the findings in chest computed tomography scans demonstrate hyperinflation but few low-attenuation areas. Relatively well-preserved DL CO and DL CO /VA provide a clue to establishing the correct diagnosis.