Bronchodilator test will be performed with albuterol and ipratropium bromide inhalation solution. FeNO levels will be measured of using the Filt's Vario analyzer which allows for bronchial or nasal tests, with a flow and volume meter Lilly-type pneumotachograph . Adherence to treatment will be assessed with the ASK-20 questionnaire and reviewing the number of prescriptions for asthma during the last 6 months.