(0807) Decreased Symptoms in Patients With Chronic Cough During pH Testing

Introduction: Chronic cough is a prevalent and challenging clinical presentation. After the most common etiologies have been explored, specialists may try various other diagnostic and therapeutic pathways to help these patients. The use of pH probe testing can objectively evaluate whether reflux remains in the differential diagnosis. Interestingly, some patients have reported decreased or absent symptoms while the pH probe is in place.

Methods: A retrospective chart review was completed for 8 adult patients with chronic cough who reported fewer symptoms while a trans-nasal pH probe was in place. Each patient underwent placement of a pharyngeal pH probe (RestechTM) or multichannel intraluminal impedance with dual pH sensors (MII-pH). A descriptive analysis of demographics, prior trials, responses to therapy, and results of reflux testing was performed.

Results: All patients (4 women, 4 men; age range 20-78 years) reported either a decrease or complete resolution of their symptoms during the time that a trans-nasal pH probe was in place. Improved symptoms included cough, mucous/throat clearing, and chest tightness. One patient observed symptoms return 90 minutes after the probe was removed. Another patient noticed similar decreased symptoms during 3 separate pH probe studies while a third patient experienced cough reduction with a pharyngeal pH probe and with MII-pH. The average number of medication trials and/or therapeutic trials including diet modification, procedures, and adjunct therapies was 10.4 with a range of 5-19. Of the patients, 3 were diagnosed with chronic refractory/unexplained cough, while others responded to treatment for upper airway cough syndrome, reflux, and asthma.

Conclusions: The observation that some chronic cough patients have decreased or absent symptoms when a trans-nasal pH probe is in place may suggest potential etiologies like neurogenic cough, somatic cough syndrome, or laryngeal penetration. This observed phenomenon warrants further study as it could lead to a more precise diagnosis and treatment plan.