Background: Inhaled corticosteroid (ICS) is a first-line therapy for both cough variant (CVA) and bronchial asthma (BA), which chronic airway inflammation underlies. We evaluated the anti-inflammatory effect of budesonide on the central and peripheral airways inflammation in patients with CVA and mild BA.
Methods: Thirty steroid-naïve patients with CVA (15) and mild BA (15) were examined during their symptom free days before and after 6 months of inhaled budesonide (800 μg/day) treatment. Induced sputum test using 3% hypertonic saline solution via an ultrasonic nebulizer was performed. The samples derived from the first 10 minutes were defined as sputum in central airways and from the next 10 minutes as in peripheral. Exhaled nitric oxide (eNO) levels and the 20 % provocative concentration of acetylcholine (PC20) were also assessed.
Results: In both patients with CVA and BA, inhaled budesonide significantly reduced the percentage of eosinophils both in central and peripheral airways.

Table 1
Eosinophils (%)4.8 ± 4.9/2.2 ± 3.8*3.6 ± 4.7/1.4 ± 2.8*11.8 ± 18.4/4.5 ± 7.8**7.5 ± 12.7/3.4 ± 5.8**
*; P<0.05 vs pre-value**; P<0.01 vs pre-value

It also significantly reduced eNO levels and increased PC20 .

Table 2
eNO level (ppb)25.8 ± 16.914.5 ± 10.8*72.8 ± 56.922.5 ± 20.8**
PC20 (μg/mL)3,005 ± 3,2895,768 ± 5,289*1,223 ± 1,8763,345 ± 3,247*
*; P<0.05 vs pre-value**; P<0.01 vs pre-value

Conclusions: Inhaled budesonide effectively suppresses inflammation of central and peripheral airways in patients with CVA and mild BA.