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

Chang, Anne B.; Phelan, P. D.; Sm, Sawyer; Brocco, Silvia; Robertson, Colin F.

doi:10.1136/adc.77.4.331

Cited by 80 publications

(64 citation statements)

References 21 publications

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“…It is possible that rhinovirus infection could be responsible for persistent cough and BDR in susceptible subjects. This study has shown that, in addition to the observations of others of increased BHR and CRS at the time of coughing [17,23], there is also increased BDR. If BDR returns to normal when cough resolves, then a common reason for both BDR and cough would be suggested.…”

Section: Discussionsupporting

confidence: 76%

Bronchodilator responsiveness and atopy in 5–10-yr-old coughers

McKenzie

Mylonopoulou²,

Bridge³

2001

Eur Respir J

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Bronchodilator responsiveness and atopy in 5-10-yr-old coughers. S.A. McKenzie, M. Mylonopoulou, P.D. Bridge. #ERS Journals Ltd 2001. ABSTRACT: Cough-variant asthma is considered by some to be an asthma phenotype. Bronchodilator responsiveness (BDR) is an undisputed feature of asthma. Of schoolaged wheezers, 90% are atopic. Are school-aged coughers who demonstrate BDR also atopic? If so, then it would be reasonable to reserve the diagnosis cough-variant asthma for this particular group.Airway resistance was measured by the interrupter technique (Rint) before and after salbutamol in controls (n=73), coughers (n=63) and previous wheezers (n=63) aged 5-10 yrs. Immunoglobulin (Ig)-E was measured in coughers and wheezers. BDR was expressed as the ratio baseline:post-salbutamol Rint.Groups were of similar age (mean 6.7, range 5-9.9 yrs). Geometric mean baseline Rint was similar in controls and coughers (0.66 and 0.68 kPa?L -1 ?s), but the baseline Rint for wheezers (0.73 kPa?L -1 ?s) was greater than that for controls (p=0.05) but not significantly different from coughers (p=0.17). Geometric mean BDR in coughers was 1.22, controls 1.13 and wheezers 1.30 (p=0.01 for coughers and controls; p=0.08 for coughers and wheezers; pv0.001 for controls and wheezers). IgE was lower in coughers than wheezers (geometric means 36 and 364 International Units (IU)?L -1 , pv0.001) and was unrelated to BDR in both groups.In summary, atopy, and not bronchodilator responsiveness, distinguishes groups of coughers from groups of wheezers. A diagnosis of cough-variant asthma cannot be reserved for even those school-aged coughers, who demonstrate bronchodilator responsiveness.

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Section: Discussionsupporting

confidence: 76%

Bronchodilator responsiveness and atopy in 5–10-yr-old coughers

McKenzie

Mylonopoulou²,

Bridge³

2001

Eur Respir J

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“…CHANG et al [26] have studied the cough-reflex sensitivity of boys and girls and found there is no sex-related difference. It is, therefore, possible that the greater sensitivity of the cough reflex seen in females arises after puberty.…”

Section: Discussionmentioning

confidence: 99%

A worldwide survey of chronic cough: a manifestation of enhanced somatosensory response

et al. 2014

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Reports from individual centres suggest a preponderance of females with chronic cough. Females also have heightened cough reflex sensitivity. Here we have reviewed the age and sex of unselected referrals to 11 cough clinics. To investigate the cause of any observed sex dimorphism, functional magnetic resonance imaging of putative cough centres was analysed in normal volunteers.The demographic profile of consecutive patients presenting with chronic cough was evaluated. Cough challenge with capsaicin was undertaken in normal volunteers to construct a concentration-response curve. Subsequent functional magnetic resonance imaging during repeated inhalation of sub-tussive concentrations of capsaicin observed areas of activation within the brain and differences in the sexes identified.Of the 10 032 patients presenting with chronic cough, two-thirds (6591) were female (mean age 55 years). The patient profile was largely uniform across centres. The most common age for presentation was 60-69 years. The maximum tolerable dose of inhaled capsaicin was lower in females; however, a significantly greater activation of the somatosensory cortex was observed.Patients presenting with chronic cough from diverse racial and geographic backgrounds have a strikingly homogeneous demographic profile, suggesting a distinct clinical entity. The preponderance of females may be explained by sex-related differences in the central processing of cough sensation. @ERSpublications Chronic cough in specialist clinics have homogenous demographic profiles, suggesting single clinical entity

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“…With this technique, capsaicin concentrations (or other tussives such as citric acid and distilled water) are doubled until two and five "cough events" (typically defined by the number of expulsive events, or "cough sounds") are achieved, representing the threshold and suprathreshold response, respectively. These studies have shown differences in the cough response between ages [13], genders [14][15][16] and diseases [4,5,13,17]. However, these data cannot infer changes in expiratory muscle activation, duration of expulsive phases and the airflow dynamics with increasing capsaicin concentration, all which are essential components in defining the cough response.…”

Section: Introductionmentioning

confidence: 98%

Capsaicin exposure elicits complex airway defensive motor patterns in normal humans in a concentration-dependent manner

Vovk

Bolser

Hey³

et al. 2007

Pulmonary Pharmacology & Therapeutics

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The airway defensive response to tussive agents, such as capsaicin, is frequently assessed by counting the number of cough sounds, or expulsive events. This method does not identify or differentiate important respiratory events that occur in the respiratory muscles and lungs, which are critical in assessing airway defensive responses. The purpose of this study was to characterize the airway defensive behaviours (cough and expiration reflex) to capsaicin exposure in humans. We observed complex motor behaviours in response to capsaicin exposure. These behaviours were defined as cough reacceleration (CRn) and expiration reflex (ERn), where n is the number of expulsive events with and without a preceding inspiratory phase, respectively. Airway defensive responses were defined in terms of frequency (number of expulsive events), strength (activation of abdominal muscles) and behaviour type (CRn vs. ERn). Thirty-six subjects (15 females, 24±4 yr) were instrumented with EMG electrodes placed over the rectus abdominis (RA), external abdominal oblique (EO) and the 8th intercostal space (IC8). A custom-designed mouth pneumotachograph was used to assess the airflow acceleration, plateau velocity and phase duration of the expulsive phase. Subjects inhaled seven concentrations of capsaicin (5-200 μM) in a randomized block order. The total number of expulsive events (frequency) and the sum of integrated EMG for the IC8, RA and EO (strength) increased in a curvilinear fashion. Differentiating the airway defense responses into type demonstrated predominately CR1 and CR2 (i.e. inspiration followed by one and two expulsive events, respectively) with very few ER's at <50 μM capsaicin. At higher concentrations (>50 μM) ER's with one or more expulsive events (≥ER1) appeared, and the number of CR's with three or more expulsive events (≥CR3) increased. The decrease in EMG activation and airflow measurements with each successive expulsive event suggests a decline in power and shear force as the number of expulsive events increased. Therefore, the airway defensive response to capsaicin is a complex motor pattern that functions to coordinate ER's and CR's with differing numbers of expulsive events possibly to prevent aspirations and keep air moving to promote clearance.

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

Cited by 80 publications

References 21 publications

Bronchodilator responsiveness and atopy in 5–10-yr-old coughers

Bronchodilator responsiveness and atopy in 5–10-yr-old coughers

A worldwide survey of chronic cough: a manifestation of enhanced somatosensory response

Capsaicin exposure elicits complex airway defensive motor patterns in normal humans in a concentration-dependent manner

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