Cough hypersensitivity syndrome is an important clinical concept: a pro/con debate

The major etiologies of chronic cough are generally accepted to consist of upper airway cough syndrome (formerly postnasal drip syndrome), eosinophilic airway inflammation (asthma, nonasthmatic eosinophilic bronchitis), and gastroesophageal reflux disease (GERD). However, only a small percentage of patients with these very common conditions suffers from chronic cough. Furthermore, acute cough due to viral upper respiratory tract infection (URI) is almost always a transient, self-limited condition, yet in a small subgroup of patients, URI heralds the onset of chronic, refractory cough. The cough hypersensitivity syndrome has been proposed to explain the occurrence of chronic cough in a subgroup of patients exposed to the same putative triggers as the vast majority of the population in whom chronic cough does not result. Although conceptually the cough hypersensitivity syndrome may be intellectually satisfying, differences of opinion remain as to whether this newly recognized entity is of clinical significance, i.e., useful for the treatment of patients suffering from chronic cough. The Third American Cough Conference, held in New York in June 2011, provided an ideal forum for the debate of this issue between two internationally recognized authorities in the field of cough.