The prolonged recovery time of pulmonary function after a severe asthma exacerbation was not shown to be directly associated with poor adherence to ICS. Therefore the results indicate that an unknown subtype of asthma may be associated with the prolonged recovery of pulmonary function time after an acute exacerbation of asthma despite regular ICS use. Further prospective studies to investigate factors affecting the recovery time of pulmonary function after an asthma exacerbation are warranted.