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At least 19 recordsLinked to original sources

PubMed2003

Enhanced cough response to hyperpnea with cold air challenge in chronic cough patients showing increased cough sensitivity to inhaled capsaicin.

BACKGROUND: Although many chronic cough patients have complained of an induced cough by cold air contact, the clinical relevance of cold air to inducing a cough and the diagnostic value of a hyperpnea with cold air (HCA) challenge to detect a hyperreactive cough reflex have not yet been investigated. METHODS: Recordings of cough counts after a 2-min HCA challenge were performed in 49 chronic cough patients and 15 healthy controls. Capsaicin cough provocation tests, which determine the threshold concentration of capsaicin that induces five or more consecutive coughs (C5), were also administered. RESULTS: After comparing the results from the capsaicin cough provocation tests of the patients and the controls, the chronic cough patients were divided into two groups: an increased cough sensitivity (ICS) group (n = 28) (C5 < 32 micromol/l) and a normal cough sensitivity (NCS) group (n = 21) (C5 >or= 32 micromol/l). The median value of induced cough counts after a HCA challenge was 11 coughs in patients with ICS and was a significantly enhanced cough response compared to that of the patients with NCS and healthy controls (four coughs, respectively). CONCLUSIONS: A simple cough provocation test using a HCA challenge may be useful for detecting ICS. It also suggests that hyperreactive cough reflexes may be one of the mechanisms of inducing chronic cough.

Administration, Inhalation↗

PubMed2003

Comparison of atopic cough with cough variant asthma: is atopic cough a precursor of asthma?

BACKGROUND: We have described a group of patients who present with isolated chronic bronchodilator resistant non-productive cough with an atopic constitution, eosinophilic tracheobronchitis, and airway cough receptor hypersensitivity without bronchial hyperresponsiveness, which we have termed "atopic cough". Although cough variant asthma (in which the cough responds to bronchodilators) is recognised as a precursor of typical asthma, it is not known whether atopic cough is also a precursor of asthma. METHODS: Eighty two patients with atopic cough were retrospectively examined for onset of typical asthma and compared with 55 patients with cough variant asthma (20 untreated patients and 35 treated with long term inhaled beclomethasone dipropionate (BDP), 218-467 micro g/day). The median follow up period for patients with atopic cough and cough variant asthma was 4.8 (1-11.5) years and 3.7 (1-12.4) years, respectively. RESULTS: Onset of typical asthma occurred in only one of the patients with atopic cough. In patients with cough variant asthma, typical asthma developed in two of 35 patients taking BDP and six of 20 untreated patients (difference 24.3%, 95% CI 2.8 to 45.8, p<0.02). CONCLUSIONS: These findings suggest that cough variant asthma is a precursor of typical asthma but that atopic cough is not. Treatment with inhaled steroids may prevent the transformation of cough variant asthma into typical asthma.

Administration, Inhalation↗

PubMed2001

Cough and gastroesophageal reflux: identifying cough and assessing the efficacy of cough-modifying agents.

From a symptom research standpoint, much has been learned about the management of cough in general and cough caused by gastroesophageal reflux disease in particular. Yet, before further advances can be made in our understanding of how to best manage patients with this common symptom, methodologic challenges remain to be solved. One of the most basic is the development of valid and reliable methods by which to identify cough, assess its impact on patients, and assess the efficacy of cough therapies. Herein, we review the characteristics of cough that relate to its assessment and how the effect of drug treatment on cough has been assessed. Perspective is provided on evaluating the efficacy of cough-modifying agents and the optimal method for identifying a cough and linking it with a reflux event. Investigators should use both subjective and objective methods, because they have the potential to measure different aspects of cough. Subjective measures, such as a cough-specific quality-of-life instruments, are likely to best reflect the severity of cough from the patient's standpoint, because a subjective response most likely integrates both cough frequency and intensity. The ideal objective method should allow cough to be automatically counted over 24 hours in an ambulatory setting. Although it is theoretically possible to design and construct such a device that is also relatively unobtrusive, reliable, and accurate, one is not yet available.

Antitussive Agents↗

PubMed2000

Candesartan cilexetil is not associated with cough in hypertensive patients with enalapril-induced cough. Multicentre Cough Study Group.

The aim of this study was to evaluate the occurrence of dry cough during treatment with candesartan cilexetil, enalapril, or placebo in patients with hypertension and a history of angiotensin converting enzyme (ACE)-inhibitor-related cough. Patients with confirmed cough during an enalapril (10 mg) challenge period, followed by no cough during a placebo dechallenge period were randomized to 8 weeks of double-blind treatment with candesartan cilexetil (8 mg) (n = 62), enalapril (10 mg) (n = 66), or placebo (n = 26). Incidence and severity of dry cough was evaluated by the symptom assessment questionnaire, frequency of dry cough by a visual analog scale, and the possible impact on quality of life by the minor symptom evaluation (MSE) profile. The percentage of patients with cough was significantly lower with candesartan cilexetil (35.5%) than with enalapril (68.2%, P < .001), and did not differ between candesartan cilexetil and placebo (26.9%, P > .20). Patients coughed less frequently and with less severe cough with candesartan cilexetil than with enalapril, and similarly with candesartan cilexetil and placebo. Changes in the MSE profile were minor, although candesartan cilexetil had better scores for contentment than placebo (P = .03), and also tended to be associated with better sleep than enalapril (P = .08). In hypertensive patients with ACE-inhibitor-induced cough, the incidence, frequency, and severity of dry cough was significantly lower with candesartan cilexetil than with enalapril, and no different from that found with placebo.

Adult↗

PubMed2001

The combined cough frequency/severity scoring: a new approach to cough evaluation in clinical settings.

Cough assessment is an important component in the clinical evaluation of patients with respiratory and cardiovascular disorders (asthma, chronic obstructive lung disease, congestive heart failure, etc.). A dry bothersome cough is the most common adverse class effect of all angiotensin-converting enzyme inhibitors (ACE-I). The present study was aimed to determine the feasibility of a new combined frequency/severity cough scoring method in patients with ACE-I induced cough before and after their modification with aspirin addition. The study was designed to compare two different regimens of active treatment: intermediate (500 mg) versus low (100 mg) dose aspirin in ACE-I cough suppression (self-matched control data) and comprised 21 patients (14 men, 7 women; mean age 62 +/- 11 years) on ACE-I treatment. ACE-I treatment was discontinued and the dry cough completely disappeared, but returned in all patients within one week (rechallenge period) after ACE-I reintroducing. Severity of cough was defined as follows: 0--no cough at all; 1--occasional hems; 2--mild, isolated cough, without additional symptoms; 3--moderate, paroxysmal cough, without additional symptoms; 4--severe, strenuous cough, accompanied by chest discomfort. In addition to cough severity score, cough frequency score (0-10) was obtained using a visual analog scale: 0 = I never cough; 10 = I cough all day. Low doses of aspirin were ineffective to suppress ACE-I induced cough. In contrast, intermediate doses completely abolished cough in 14 patients and reduced coughing in all but one patient. Cough severity and cough frequency scores decreased, respectively, from 2.6 +/- 1.1 to 0.7 +/- 1.0 (p<0.001) and from 6.9 +/- 2.2 to 2.1 +/- 2.4 (p<0.0001). Overall, the cough frequency score method alone could identify a beneficial modification of cough in 17 (81%) patients and cough severity score method alone in 17 (76%). Using the combined cough frequency/severity scoring, a beneficial modification of cough could be identified in 20 (95%) of patients. The new combined cough frequency/severity scoring is suitable for clinical practice and can improve the identification of dynamic cough modifications during treatment period as compared with the conventional frequency score method. It may have important implications in the evaluation of patients with respiratory and cardiovascular disorders.

Aged↗

PubMed1999

Cough, cough receptors, and asthma in children.

This review discusses current general concepts on cough and the relationship between cough, cough receptor sensitivity, and asthma in children. It presents models of the relationship between cough and bronchoconstriction, and proposes a new model outlining the relationship between cough receptor sensitivity, airway hyperresponsiveness, and the clinical issues of cough, wheeze, and dyspnea in children with and without asthma. Cough is very common in children, with a prevalence of 15-20%. Those with non-specific cough (dry cough in the absence of identifiable respiratory illness) are often treated with a variety of drugs, in particular, medications for asthma and gastroesophageal reflux. However, there is little evidence to use these medications for the sole symptom of cough in children. Clinical studies on cough need to be interpreted in light of inherent methodological problems in studying cough. These methodological problems include the nonrepeatable nature of questions on cough, the unreliability of subjective measurements of cough, the lack of objective measurements to quantify cough severity, and the period effect (spontaneous resolution of cough). Although cough can be troublesome, cough serves as an important function for maintaining normal health of the respiratory system. The importance of cough in maintaining respiratory health is reflected in the development of lung atelactasis/collapse from retained secretions and recurrent pneumonia in clinical situations where the cough reflex is ineffective. The cough reflex is complex and still poorly understood. In this article the simplified cough pathway is presented and involves cough receptors, mediators of sensory nerves and the afferent pathway, the vagus nerve, the cough centre, efferent pathway, and cough effectors.

Adolescent↗

PubMed1995

A Comparison of the Cough Profile of Fosinopril and Enalapril in Hypertensive Patients with a History of ACE Inhibitor-Associated Cough.

OBJECTIVE: Cough frequency and severity with fosinopril and enalapril were assessed in hypertensive patients with previous angiotensin-converting enzyme inhibitor (ACEI)-associated cough. DESIGN: Prospective, multicenter, randomized, 8-week double-blind treatment. PATIENTS: One hundred seventy-nine patients (mild-to-moderate hypertension, nonsmokers, mean age 58 years; 55% females; 72% Caucasian, 6% black, 19% Hispanic) were studied. Patients with other cough etiologies, significant co-morbidity, or confounding medications were excluded. INTERVENTIONS: Patients were randomized to fosinopril 10 mg (n = 85) or enalapril 5 mg (n = 94) once daily. Dosage could be doubled for blood pressure control after 4 weeks. Outcome measurements: The primary end point was all-cough frequency based on patient daily diary ratings; a cumulative cough frequency score was calculated. Secondary end points included cough severity, nonproductive cough frequency, night awakenings, cough time of day, and spontaneously reported cough. RESULTS: Fosinopril and enalapril demonstrated similar blood pressure control. Significant cough profile differences were observed in favor of fosinopril: all-cough frequency was 40.6 plus minus 3.8 (mean plus minus SE) versus 52.8 plus minus 3.6 (p = 0.02); nonproductive cough frequency was 26.7 plus minus 3.5 versus 40.3 plus minus 3.4 (p less-than-or-equal 0.01); and cough time of day was 49.2 plus minus 5.2 versus 66.0 plus minus 5.0 (p = 0.02), for fosinopril and enalapril, respectively. Subgroup analysis revealed all-cough frequency was 33.5 plus minus 6.3 versus 56.6 plus minus 5.3 (p = 0.006) for fosinopril and enalapril, respectively, in patients who previously had cough on one of these two ACEI (predominantly enalapril). Ten (12%) fosinopril and 25 (27%) enelapril patients spontaneously reported cough (p = 0.01). CONCLUSIONS: Hypertensive patients with previous ACEI-associated cough reported less frequent cough with fosinopril compared to enalapril, based on cumulative patient diary scores and spontaneously reported cough. This difference was most apparent in the subgroup of patients who previously experienced cough associated with enalapril therapy. Patients with prior ACEI-associated cough may experience less frequent with fosinopril.

Journal Article↗

PubMed1994

Capsaicin cough sensitivity decreases with successful treatment of chronic cough.

To assess the role of enhanced cough sensitivity in the pathogenesis of cough, we measured cough severity on a visual analogue scale (VAS) and capsaicin cough sensitivity (the concentration required to elicit two [C2] and five [C5] coughs) in 87 consecutive patients referred with chronic cough. Measurements were repeated after complete investigation and treatment, when patients were entered into one of four study groups: (1) treatment success (primary cause of cough successfully treated with elimination of the cough, n = 48); (2) primary treatment failure (treatment of potential primary cause of cough unsuccessful, n = 12); (3) cough treatment failure subgroup A (potential primary cause of cough identified and successfully treated but no improvement in cough, n = 8); and (4) cough treatment failure subgroup B (no potential primary cause of cough identified, n = 19). All patients in groups 3 and 4 were nonsmokers, had normal chest radiography and negative histamine challenge test, and failed to respond to intensive empirical treatment for rhinitis and gastroesophageal reflux. The VAS cough severity was lower and log C2 and C5 higher after treatment compared with initial values in the treatment success group but not in the other three groups. Enhanced sensitivity of airway nerves that mediate cough is important in the pathogenesis of nonproductive cough, and successful treatment is associated with a reduction in cough sensitivity. While enhanced sensitivity of airway nerves is usually present in patients with identifiable causes of chronic nonproductive cough, it is also found in other patients in whom the cause of cough is unknown.

Adult↗

PubMed2002

Cough sensitivity and extrathoracic airway responsiveness to inhaled capsaicin in chronic cough patients.

Enhanced cough response has been frequently observed in chronic cough. Recently, extrathoracic airway constriction to inhaled histamine was demonstrated in some chronic cough patients. However, relation between extrathoracic airway hyperresponsiveness (EAHR) and cough sensitivity determined by capsaicin inhalation is unclear in each etiological entity of chronic cough. Seventy-seven patients, with dry cough persisting for 3 or more weeks, normal spirometry and chest radiography, and 15 controls, underwent methacholine bronchial provocation test and capsaicin cough provocation test. Elicited cough number and flow-volume curve was examined after inhalation of capsaicin to evaluate cough sensitivity and EAHR. Thirty-three patients, with postnasal drip, showed normal extrathoracic airway responsiveness, and 27 of them showed normal cough sensitivity to capsaicin. Cough sensitivity was enhanced in 14 patients with cough variant asthma (CVA) who showed bronchial hyperresponsiveness; EAHR to inhaled capsaicin was present in 12 of them. The remaining 30 patients were tentatively diagnosed as idiopathic chronic cough (ICC). Eleven ICC patients showed enhanced cough sensitivity and EAHR to inhaled capsaicin while 19 patients showed normal values. These results indicate that cough sensitivity is closely related with extrathoracic airway responsiveness during capsaicin provocation in some chronic cough patients. EAHR and enhanced cough sensitivity to inhaled capsaicin may be a part of mechanism developing chronic cough.

Administration, Inhalation↗

PubMed1994

Coughing frequency in patients with persistent cough: assessment using a 24 hour ambulatory recorder.

Cough is an important symptom of many respiratory disorders. We determined the frequency and diurnal variation of cough in normal subjects and in patients with asthma or with persistent cough of unknown cause. We used a portable, solid-state, multiple-channel recorder to record cough sounds over a 24 h period. The audio-signal was recorded from a unidirectional microphone strapped over the chest wall, and electromyographic (EMG) signals from the lower respiratory muscles were simultaneously registered with surface electrodes. The recorded digital data were examined on an IBM-compatible computer, and the typical signals induced by cough (as assessed by voluntary or experimentally-induced cough) were counted. In 12 normal subjects, only 0-16 coughs were recorded over 24 h. In 21 stable asthmatics with a history of chronic cough ("asthma") the median number was 282 (ranges: 45-1,577), and in 14 patients with the predominant symptom of daily dry coughs ("chronic coughers") the median number was 794 (64-3,639). In both groups of patients, there was a diurnal variation of coughs, such that the least numbers occurred between 2 and 5 a.m. (< 3% of total). In the asthma group, there was no significant correlation between forced expiratory volume in one second (FEV1) (% predicted) or diurnal variation of peak expiratory flow and cough frequency. In the chronic coughers, there was a significant correlation between daytime cough numbers and daytime cough symptoms scores but not for the night-time values. Our data show that cough frequency is not determined by the severity of asthma in relatively stable asthmatics on inhaled steroids, and is reduced during sleep in both asthmatics and chronic cough patients. This portable cough recorder may be useful in the assessment of drug therapy for chronic cough.

Adult↗

PubMed1990

The effect of sulindac on the abnormal cough reflex associated with dry cough.

In order to determine the possible role of prostaglandins in the abnormal cough reflex in patients with dry cough, the effects of a cyclooxygenase inhibitor on cough symptoms were examined. This was measured by a cough symptom score and by the cough reflex sensitivity to inhaled capsaicin in a double blind, randomized, cross-over study comparing the effects of placebo with sulindac, 200 mg daily for 1 week. We studied six hypertensive patients with angiotensin converting enzyme inhibitor-associated cough and six patients with an idiopathic, dry, unproductive cough, all of whom had an increase in the sensitivity of the cough reflex. There was no change in blood pressure control in the hypertensive patients during sulindac therapy. The patients with the angiotensin converting enzyme-associated cough had a significant reduction in the cough symptom score and also a significant increase in the dose of capsaicin causing two or more coughs (threshold sensitivity) and that causing five or more coughs (near maximum response) during sulindac therapy as compared to placebo. In those patients with idiopathic, dry, unproductive cough, sulindac did not alter the symptom of cough or the cough reflex response to capsaicin. These results suggest that prostaglandins may be involved in cough associated with angiotensin converting enzyme inhibitor therapy, but are less likely to be important in the pathogenesis of more common dry coughs of unknown cause.

Aged↗

PubMed2001

Application and validation of a computerized cough acquisition system for objective monitoring of acute cough: a meta-analysis.

STUDY OBJECTIVE: The purpose of the meta-analysis was to understand the antitussive effect of treatment with dextromethorphan hydrobromide, 30 mg, vs placebo over a 3-h treatment period in patients with cough due to uncomplicated upper respiratory tract infection (URTI), and to show that the computerized system for acquisition and analysis of cough sound was consistent and reproducible across the individual studies. STUDY DESIGN: The six studies used for the meta-analysis were randomized, double-blind, parallel-group, single-dose, placebo-controlled studies with a 3-h postdose cough evaluation period. SETTING: One study was conducted in Durban, South Africa, and five studies were conducted in Bombay, India. Four studies took place in clinics, and two studies were in-home studies. PATIENTS: Seven hundred ten adult patients with cough due to uncomplicated URTI who were otherwise healthy and who satisfied the inclusion/exclusion criteria for the meta-analysis. MEASUREMENTS AND RESULTS: For each patient, a standard baseline was calculated pretreatment, then a 3-h continuous cough recording was made after treatment was initiated. Five efficacy variables were measured in 30-min intervals: cough bouts, cough components, cough effort, cough intensity, and cough latency. The meta-analysis showed consistent results across most of the studies for each of the efficacy variables. It demonstrated significantly greater overall reductions in cough bouts, cough components, and cough effort, and an increase in cough latency for patients treated with dextromethorphan hydrobromide, 30 mg, vs those treated with placebo. CONCLUSION: The results of a meta-analysis of the six clinical studies show that the antitussive effect of a single dose of dextromethorphan hydrobromide, 30 mg, has been established. The consistent nature of the results shows that the computerized cough acquisition and analysis system is a valid and reproducible methodology for evaluating cough associated with URTI.

Adolescent↗

PubMed1992

Sensitivity of the cough reflex in patients with chronic cough.

Cough may occur in association with excess bronchial secretions and may, therefore, be productive. However, in a proportion of patients the cough is non-productive and a possible association with an enhanced response of the cough reflex has been postulated. Using the irritant capsaicin, the sensitivity of the cough reflex was measured in 363 individuals. A questionnaire was used to divide subjects into three groups: Group A) non-coughing controls; Group B) subjects with non-productive cough; and Group C) subjects with productive cough. The group means (+/- 99% confidence interval (CI)) of the log capsaicin concentration causing two or more coughs (C2) for groups A, B, C were 0.98 (+/- 0.08), 0.64 (+/- 0.09) and 1.04 (+/- 0.23), respectively. The log capsaicin concentration causing five or more coughs (C5) for groups A, B, C were 1.78 (+/- 0.1), 1.16 (+/- 0.12) and 1.54 (+/- 0.25), respectively. Group B was significantly more sensitive to inhaled capsaicin than the other groups (p less than 0.01). No significant difference was observed between groups A and C. Some differences were found when subgroups were examined within groups B and C. In group B, patients with post-nasal drip were found to have a normal sensitivity of the cough reflex and were, therefore, different from the remainder of patients with non-productive cough. In group C, patients with bronchiectasis and current infection showed an increase in the sensitivity of their cough reflex. It is concluded that cough can occur in association with either excess mucus production leading to productive cough or an increase in the sensitivity of the cough reflex, possibly leading to non-productive cough.

Administration, Inhalation↗

PubMed1995

Resolution of ACE inhibitor cough: changes in subjective cough and responses to inhaled capsaicin, intradermal bradykinin and substance-P.

1. In eight hypertensive patients with ACE inhibitor-induced cough the resolution of the cough was examined in a prospective observational study over 4 weeks duration. Resolution of cough was measured by visual analogue scales and questionnaire at baseline and days 3, 7, 14 and 28. In addition changes in cough sensitivity to inhaled capsaicin, and skin responses to bradykinin and substance-P were measured at the same time points. 2. All patients recorded significant subjective improvement in cough questionnaire scores for severity and night time waking, and by visual analogue scales for severity and frequency of cough (all P < 0.0005 for trend from day 0-28). Significant changes in subjective measures were recorded by 3 to 7 days for most measures, but further reductions were observed up to day 28 (all P < 0.01 day 28 vs day 0). 3. The sensitivity to inhaled capsaicin fell over the 28 days of study after stopping enalapril. The potency of capsaicin relative to day 0 was reduced to 0.25 (95% CI 0.07-0.87) by day 14, and to 0.20 (95% CI 0.06-0.67) by 28 days. 4. After stopping enalapril there was a highly significant reduction in wheal area produced by intradermal bradykinin, with the majority of the effect seen by day 3 (P < 0.0005). The wheal area to intradermal substance-P also declined with time after stopping enalapril, but significant changes were not observed until 14 days (P < 0.01). 5. Multiple regression analysis of the rates of decline for the subjective and objective measures of cough showed significant associations between the response to inhaled capsaicin and the VAS scores for severity of cough (P = 0.005) and frequency of cough (P = 0.011). Capsaicin response was not related significantly to the severity of cough measured by self-administered questionnaire. 6. There was a significant association between bradykinin response and VAS scores for frequency of cough (P < 0.04) and severity of cough (P < 0.05), but not with cough by questionnaire or the capsaicin response. The response to substance-P did not relate significantly to any of the measures of cough. 7. Cough caused by enalapril improved markedly by 14 days but took up to 28 days to resolve. It was associated with increased sensitivity to inhaled capsaicin which decreased over 28 days, and which paralleled changes in subjective cough scores.

Adult↗

PubMed1996

[Effects of inhaled anticholinergic agents and beta 2-agonists on distilled water induced cough in patients with chronic cough].

The purpose of this study was to evaluate the usefulness of ultrasonically nebulized distilled water (UNDW) inhalation for assessing cough receptor sensitivity and also the effects of inhaled anticholinergic agents and beta 2-agonists on the number of coughs induced by the UNDW inhalation in patients with chronic cough. All patients were non-smokers and had neither bronchial hyperreactivity nor atopic status. We studied the effects of inhaled oxitropium bromide (300 micrograms) and fenoterol hydrobromide (600 micrograms) on the number of coughs induced by UNDW inhalation for 3 minutes in 9 patients with chronic cough and the effects of inhaled fenoterol hydrobromide (400 micrograms) on the number of coughs induced by UNDW inhalation for 1 minute in 8 patients with chronic cough using a randomized, double-blind, cross-over method. There was no significant difference in pulmonary function test results before and after UNDW inhalation. In both the 3-minute and 1-minute UNDW inhalation studies, the number of coughs was greater in the patients than in normal subjects. Patients with chronic cough may have a high level of cough sensitivity, inhaled fenoterol significantly reduced the number of coughs in the patients in both the 3-minute and 1-minute UNDW inhalation studies (p < 0.05). However, compared with control, inhaled oxitropium did not reduce the number of coughs caused by the 3-minute UNDW inhalation in the patients. Tachyphylaxis was observed in normal subjects in the 3-minute UNDW inhalation study when repeated at a 30-minute interval. We conclude that 1-minute UNDW inhalation method may be safe and useful for measuring cough receptor sensitivity of patients with chronic cough and that inhaled beta 2-agonists may have an inhibitory effect on cough induced by irritation of cough receptors through unknown mechanisms other than the bronchodilator effect.

Administration, Inhalation↗

PubMed2003

Elevated substance P levels in nasal lavage fluids from patients with chronic nonproductive cough and increased cough sensitivity to inhaled capsaicin.

BACKGROUND: The exact mechanism of a chronic nonproductive cough is sometimes unclear when patients who are without symptoms or signs indicating the major causes of chronic cough remain undiagnosed. OBJECTIVE: We hypothesized that some neurochemical alterations in the sensory nerves in the cough reflex may occur in the upper airway of chronic nonproductive cough patients. METHODS: We took nasal lavage fluid (NLF) specimens from 38 patients with a chronic nonproductive cough as the sole presenting symptom. All 38 had normal chest radiography, spirometry, and bronchial responsiveness. We likewise took NLF specimens from 14 healthy control subjects. We used a capsaicin cough provocation test to determine cough sensitivity and considered the value of C5 (the lowest capsaicin concentration inducing 5 consecutive coughs) as an index of cough sensitivity. We measured levels of substance P of NLF specimens by using ELISA. In addition, we evaluated the clinical response of each patient after subsequent therapeutic trials with an antihistamine and decongestant for 2 weeks. RESULTS: By using capsaicin cough sensitivity as the basis for grouping the study subjects, we divided the patients into 2 groups: an increased cough sensitivity group (ICS, C5 <32 mumol/L) and a normal cough sensitivity (NCS) group. Patients with ICS showed an elevated SP concentration in NLF (median value, 408 pg/mL) compared with that of the NCS group (237 pg/mL) and the control subjects (138 pg/mL) (P <.01). The median value of the percentage of remnant cough after therapeutic trial compared with the cough status before treatment was significantly higher in the ICS subgroup (70%) than that of NCS (25%) (P <.05). CONCLUSIONS: Elevated substance P contents in NLF specimens were associated with ICS in patients with chronic nonproductive cough, suggesting a neurochemical abnormality in the upper airway.

Administration, Inhalation↗

PubMed2003

Longitudinal decline in pulmonary function in atopic cough and cough variant asthma.

OBJECTIVE: Cough variant asthma and atopic cough are different clinical manifestations of eosinophilic airway inflammation presenting with isolated chronic non-productive cough. The aim of this study was to examine the longitudinal change in pulmonary function in cough variant asthma and atopic cough. METHODS: Longitudinal change in FEV1 was prospectively examined in 20 patients with cough variant asthma, 14 patients with atopic cough and 271 asymptomatic healthy subjects. All were lifetime non-smokers. Of the 20 cough variant asthma patients, 13 were taking long-term inhaled corticosteroid therapy (ICS) (beclomethasone dipropionate 615 +/- 58 micro g/day) and the other seven were not. Spirometry was taken at first visit, after cough was almost completely relieved on therapy, and at least once every year for 5 or more years afterwards. RESULTS: The slope of longitudinal change in FEV1 was not significantly different among cough variant asthma patients (- 0.029 +/- 0.007/year), atopic cough patients (- 0.021 +/- 0.022/year) and asymptomatic subjects (- 0.028 +/- 0.002 L/year). In patients with cough variant asthma, the slope in patients not taking inhaled corticosteroids (ICS) was 0.032 +/- 0.007 L/year, which was not significantly different from that in patients taking ICS (- 0.027 +/- 0.010 L/year). CONCLUSION: Pulmonary function decline is not greater in cough variant asthma than atopic cough and the normal population, and long-term ICS has no effect on the decline in cough variant asthma.

Asthma↗

PubMed1997

Cough sensitivity in children with asthma, recurrent cough, and cystic fibrosis.

In adults, cough sensitivity is influenced by gender and is heightened in those with non-productive cough. This study examined if cough sensitivity is (i) altered in children with asthma, recurrent cough, and cystic fibrosis and (ii) influenced by age, gender, or forced expiratory volume in one second (FEV1). Cough sensitivity to capsaicin and spirometry were performed on 209 children grouped by the diagnosis of asthma, recurrent dry cough, cystic fibrosis, and controls. Cough sensitivity was increased in children with recurrent cough, and lower in children with cystic fibrosis when compared with children with asthma and controls. Age influenced cough sensitivity in the controls. In the asthmatics, FEV1 (% predicted) correlated to cough sensitivity measures. There was no gender difference in cough sensitivity. It is concluded that cough sensitivity is different among children with recurrent dry cough, asthma, and cystic fibrosis. In children, age, but not gender, influences cough sensitivity measures and when cough sensitivity is used in comparative studies, children should be matched for age and FEV1.

Adolescent↗