Chronic Cough: The Spectrum and Frequency of Causes, Key Components of the Diagnostic Evaluation, and Outcome of Specific Therapy

Abstract

A successful, systematic, anatomic, diagnostic protocol for evaluating patients with chronic cough was presented in 1981. To determine whether it was still valid, we prospectively evaluated, over a 22-month interval, 102 consecutive and unselected immunocompetent patients complaining of cough an average of 53 +/- 97 months (range, 3 wk to 50 yr). Utilizing the anatomic, diagnostic protocol modified to include prolonged esophageal pH monitoring (EPM), the causes of cough were determined in 101 of 102 (99%) patients, leading to specific therapy that was successful in 98%. Cough was due to one condition in 73%, two in 23%, and three in 3%. Postnasal drip syndrome was a cause 41% of the time, asthma 24%, gastroesophageal reflux (GER) 21%, chronic bronchitis 5%, bronchiectasis 4%, and miscellaneous conditions 5%. Cough was the sole presenting manifestation of asthma and GER 28 and 43% of the time, respectively. While history, physical examination, methacholine inhalational challenge (MIC), and EPM yielded the most frequent true positive results, MIC was falsely positive 22% of the time in predicting that asthma was the cause of cough. Laboratory testing was particularly useful in ruling out suspected possibilities. We conclude that the anatomic diagnostic protocol is still valid and that it has well-defined strengths and limitations.

Chronic cough and gastro-oesophageal reflux: a double-blind placebo-controlled study with omeprazole

“…These four conditions are responsible for chronic cough in~90% of cases [2,3]. GOR has been found to cause 10±40% of chronic cough [1±5] which may be the only manifestation of otherwise asymptomatic GOR [2, 3, 6±8].…”

“…However, one of these studies did not statistically compare placebo and omeprazole groups and the majority of "responders" were found during open uncontrolled omeprazole treatment after the placebo control [19], and the second has been published only in abstract form [18]. With H 2 -blockers, treatment periods ranging from 2 weeks to 6 months have been required before GOR related cough has been relieved [2,18]. There is evidence that two months treatment with omeprazole is sufficient to reduce cough in patients with GOR [16].…”

Cough and gastroesophageal reflux: From the gastroenterologist end

“…It is known that a high proportion of patients with GER-related chronic cough do not have heartburn or regurgitation. [5][6][7][8] …”

Rhinosinusitis, laryngopharyngeal reflux and cough: An ENT viewpoint

“…[6][7][8] The opinion in the UK has been somehow different as observed in various publications (table 2). 9 PND refers to the sensation of nasal secretions at the back of the throat (or of a 'drip'), often resulting in the need to clear the throat and is associated with nasal stuffiness or nasal discharge.…”

“…In addition, in our cohort of chronic cough, a smaller proportion of patients were labelled as having the PND syndrome as causing their cough, 14 compared to earlier studies. [6][7][8] We have examined in a pilot study the relationship between PND syndrome and cough by recruiting patients presenting with a chronic cough and who also complained of PND, described as mucus in the back of the throat or as nasal catarrh, and observing the effects of local specific treatments applied to the nose and sinuses on the cough. 15 An improvement in the cough symptom has been shown as a response to local nasal treatment in this group of patients.…”