[The impact of inhaled corticosteroids on cough and bronchial hyperreactivity in cough variant asthma]

Classic asthma is characterized by cough, wheezing and dyspnea. Cough, however, may be the sole presenting symptom of asthma and this type of asthma is known as cough-variant asthma. The therapeutic approach to cough variant asthma is similar to that of the typical form of asthma. A diagnosis of cough-variant asthma is made when a chronic cough is associated with airway hyperresponsiveness and a favorable response to asthma therapy in the absence of other discernible cause. The aims of this study were to analyse the influence of inhaled corticosteroids on cough and bronchial hyperresponsiveness.

The study included 55 patients with cough as the sole presenting symptom. 40 patients (Group A) were treated with inhaled corticosteroids and beta2 agonists for eight weeks while 15 patients (Group B) were treated only with oral beta2 agonists. The nonspecific bronchoprovocative test with histamine was performed on all the patients before the treatment and after the examination and there was established the provocative dose of histamine causing the 20% fall in FEVI (PD20).

At the end of the study in Group A we found a statistically significant decrease of PD20 0.98 +/- 0.86 vs. 1.58 +/- 1.06 (p < 0.005), while in Group B there were no significant changes. In 90% of the patients treated with inhaled corticosteroids the cough was completely relieved while in 80% of the patients treated with only beta2 agonists the cough has remained unchanged.

Inhaled corticosteroids are choice drugs for the treatment of cough-variant asthma because they relieve cough and decrease bronchial hyperresponsiveness, thus ultimately reducing the risk of classic asthma.