The purpose of this study is to determine whether the capsaicin challenge can improve the diagnosis, treatment, monitoring and follow-up in patients with chronic cough.

Capsaicin is administrated in incremental concentrations with two inhalations of normal saline solution. Patients are instructed to exhale to functional residual capacity and than to inhale through the mouthpiece for 1 second (single breath inhalation). The number of coughs in the first 10 seconds after each inhalation is counted. C2; the concentration of which the patient responded by 2 coughs, C5;the concentration of which the patient responded by 5 coughs. The challenge ends at C5.

Inclusion Criteria:

• Patients with persisting cough for more than 3 months, without known respiratory or lung diseases

Exclusion Criteria:

• Diagnosis of respiratory or lung diseases of any kind