The Past, Present, and Future Care for Refractory Chronic Cough in Children and Adults.

Chronic cough without explanation or diagnosis has been described in medical books for over 300 years. Since 1977, some comorbidities, such as gastroesophageal reflux and post-nasal drip, have been attributed to be causes of otherwise unexplained chronic cough. Since 2005, publications have reported that unexplained chronic cough could be a distinct entity refractory to usual treatment. This was explained by dysregulation of cough centers involving the brainstem, subcortical, and cortical areas for which a neuromodulator would be essential for treatment. However, an 1886 publication described this disorder as a type of involuntary habit, and recommended treatment to break the habit. Supporting this alternative paradigm were studies that showed the urge to cough may have resulted from local airway inflammation with increased mucosal nerve density caused by the frequent daily coughing. The result was a vicious cycle where coughing caused the urge to cough, leading to repetitive daily coughing. Treatment has been demonstrated by a behavioral technique that breaks the habit. That behavioral technique, called suggestion therapy, has been highly successful in children and is now recognized as the standard of care for this disorder at pediatric referral centers. The proof of concept that suggestion therapy is effective in adults with refractory chronic cough has been demonstrated in selected adults but is not yet a common practice at specialty cough centers.