Physical Therapy Treatment of Impaired Chest Mobility in Patients with Airway Sensory Hyperreactivity.

BACKGROUND AND PURPOSE: In sensory hyperreactivity (SHR), patients have symptoms from the airways and the chest induced by environmental irritants like scenting products and cigarette smoke. They are characterized by increased cough reaction to inhaled capsaicin compared with healthy controls. Lung function tests are normal, and asthma medications have no or little effect. In a recent published article, patients with SHR were found to have impaired chest mobility and increased pain sensitivity. The purpose of this study was to evaluate if a physiotherapeutic intervention can increase chest mobility in SHR, influence these patients' symptoms and reduce capsaicin cough sensitivity. METHODS: Forty-one SHR patients were initially randomized in to groups, one for training and one for symptom registration in this controlled training study. It consisted of a daily training programme containing simple movements to increase the flexibility of the chest, a breathing exercise and a relaxation session as well as symptom registration. Chest expansion was measured with a measuring tape and thoracic and abdominal movement with light sensors. Pain sensitivity was assessed using pressure algometry and a standardized capsaicin inhalation threshold provocation-evaluated cough sensitivity. RESULTS: Twenty seven patients were left for analyses after 12 weeks and 26 patients after 24 weeks. Chest mobility and upper thoracic respiratory movements improved (p < 0.01), feeling of chest pressure and the capsaicin cough sensitivity decreased (p < 0.01). The patients also showed of significantly lowered pain pressure thresholds measured with algometry, compared with healthy controls (p < 0.001). CONCLUSION: Improvement of chest mobility after physiotherapeutic intervention indicates that these patients may have acquired a dysfunctional breathing pattern. The regular use of a training programme and structural breathing instructions can be used to improve chest mobility, chest symptoms and capsaicin cough sensitivity in patients with SHR and signs of dysfunctional breathing. Copyright © 2016 John Wiley & Sons, Ltd.

Cough reduction using capsaicin.

UNLABELLED: Chronic unexplained cough triggered by environmental irritants is characterized by increased cough reflex sensitivity, which can be demonstrated by means of inhaled capsaicin. Topical capsaicin can be used to improve non-allergic rhinitis and intestinal hypersensitivity and to reduce neuropathic pain. OBJECTIVES: We established whether an oral intake of natural capsaicin (chilli) could desensitize the cough reflex and improve unexplained coughing. METHODS: Twenty-four patients with irritant-induced, unexplained chronic cough and 15 controls were included in the study. For 4 weeks, the participants took capsules with pure capsaicin, and for 4 weeks, they took placebo capsules. The protocol was crossover, randomized, and double blind. Cough sensitivity during the study was evaluated by a standardized capsaicin inhalation cough test that assessed the capsaicin concentration required to reach two coughs (C2) and five coughs (C5). Participants were also administered questionnaires on cough and cough-related symptoms. RESULTS: Three patients withdrew before the study end, one during the active treatment period and two during the placebo period. After treatment with capsaicin, the thresholds for C2 were higher (improved) both in patients (p < 0.020) and in controls (p < 0.0061) compared to after the placebo period. Among patients, the concentration needed to reach C2 (p < 0.0004) and C5 (p < 0.0009) increased after the period with the active substance compared to cough thresholds at baseline. The cough symptom scores improved after 4 weeks of active treatment (p < 0.0030) compared to the baseline scores. CONCLUSION: Capsaicin powder taken orally decreased capsaicin cough sensitivity and cough symptoms. The findings suggest a desensitization of the cough-sensitive transient receptor potential vanilloid-1 (TRPV1).

Inhalation of menthol reduces capsaicin cough sensitivity and influences inspiratory flows in chronic cough.

INTRODUCTION: Chronic cough is a common clinical problem and there is a shortage of effective treatments for it. Within the group of transient receptor potential ion channels a receptor for the cooling substance menthol has been identified. This study aimed to assess whether pre-inhalation of dissolved, nebulised menthol could increase capsaicin cough thresholds and influence spirometric values. METHODS: Fourteen patients with chronic cough and airway sensitivity to environmental irritants and 15 control subjects were tested on three occasions. Each one inhaled a 1 mL of nebulised menthol solution of 0.5% or 1% or placebo (saline with 0.05% menthol) at each visit in a randomized and double-blind order. They were then provoked by capsaicin inhalation. RESULTS: Patients' cough thresholds differed significantly from the controls' on all three provocations (P < 0.0001). After inhalation of 1% menthol, the patients' cough thresholds were significantly higher (P < 0.02) compared to after placebo inhalation and to after 0.5% menthol inhalation (P < 0.05). The patients' peak inspiratory flows were significantly reduced after inhalation of the placebo (saline) (P < 0.05) but not after inhalation of 0.5% or 1% menthol. Forced inspiratory flows 50% were lowered after inhalation of placebo and of 0.5% menthol (P < 0.05) but not after 1% menthol. Among the controls, forced inspiratory flows 50% were lowered after only placebo inhalation (P < 0.05). CONCLUSIONS: In patients with chronic cough, pre-inhalation of menthol reduces cough sensitivity to inhaled capsaicin and influences inspiratory flows. The findings may provide scientific support for the common practice of using menthol as a reliever for variant airway discomfort. The use of menthol in different cigarette brands could be questioned since it could conceal the natural irritation following smoking.

Sensitivity to environmental irritants and capsaicin cough reaction in patients with a positive methacholine provocation test before and after treatment with inhaled corticosteroids.

BACKGROUND: Increasing evidence points to a potential role for members of the transient receptor potential family of cation channels on several features of asthmatic disease. The cough sensitivity to inhaled capsaicin is known to reflect the reactivity of these airway sensory nerves. OBJECTIVE: The aim was to study, among patients having a positive methacholine provocation and diagnosed with asthma, capsaicin cough sensitivity, sensitivity to methacholine, and levels of exhaled nitric oxide before and after treatment with inhaled steroids, and further, to measure the self-reported impact from environmental irritants. METHODS: Eighteen steroid-naïve patients with a positive methacholine test underwent capsaicin inhalation provocation on two occasions, before and after regular use of inhaled steroids over at least 3 months. Comparisons were made to 21 healthy controls. Sensitivity to methacholine and levels of exhaled nitric oxide were measured before and after the treatment. The participants also answered a validated questionnaire regarding environmental irritants. RESULTS: The patients displayed higher capsaicin cough sensitivity than the controls before the treatment period, but not afterward. Before treatment, capsaicin cough answer correlated significantly with levels of exhaled nitric oxide, but not with methacholine sensitivity. After treatment with inhaled corticosteroids, the capsaicin cough sensitivity and the inflammatory parameters were normalized. In comparison to the control group, the patients reported more affective reactions to and behavioral disruptions induced by environmental irritants. CONCLUSIONS: In steroid-naïve patients with a positive methacholine test, there is a link between that part of the airway inflammation that is reflected by exhaled nitric oxide and that followed by an augmented reactivity of capsaicin-sensitive sensory nerves. This association disappears after steroid treatment.

Inhalation method determines outcome of capsaicin inhalation in patients with chronic cough due to sensory hyperreactivity.

BACKGROUND: For patients with idiopathic chronic cough, a subgroup is recognised with respiratory symptoms induced by scents and chemicals. The diagnosis of sensory hyperreactivity (SHR) has been suggested for this group of patients and can be made using a capsaicin inhalation test. The aim of the present study was to compare the results of inhaling capsaicin by tidal breathing with those obtained by the dosimeter method regarding repeatability, agreement, and ability to distinguish patients with SHR from healthy controls. METHODS: A total of 15 patients with chronic cough due to SHR and 15 healthy control subjects underwent a randomised cross-over protocol and were provoked in a double-blind, randomised fashion with vehicle and two concentrations of inhaled capsaicin, using either the tidal breathing or dosimeter method, in a total of four challenges opportunities, two with each method. RESULTS: Patients coughed more and showed more respiratory symptoms than healthy controls with each dose of capsaicin. Compared with tidal breathing, inhalation of capsaicin with the dosimeter method caused a significantly greater number of coughs and respiratory symptoms in both patients and controls. Among the patients, the mean number of coughs after inhalation of 1 mL of capsaicin 0.4 micromol/L from the first provocation with tidal breathing was 12 (95% CI: 7; 17) and after inhalation from the first provocation with the dosimeter method 32 (95% CI: 19; 46) (P < 0.05). Both methods showed good repeatability and similar ability to distinguish patients with SHR from healthy control subjects. CONCLUSIONS: For patients with SHR, capsaicin cough sensitivity is increased and repeatable. The dosimeter method caused more coughs and other respiratory symptoms than the tidal breathing method, indicating that the methods cannot be used interchangeably. Knowledge of the type of inhalation device used, the particle size, the airflow rate and the inspiratory flow rate are essential when comparing different studies of capsaicin-induced cough.

Capsaicin cough sensitivity in allergic asthmatic patients increases during the birch pollen season.

BACKGROUND: A change in neural responsiveness may occur as the result of allergic inflammation in the lower airways as well as in the upper airways. In the lower airways, capsaicin cough sensitivity is known to reflect sensory neural reactivity. OBJECTIVE: The aim of this study was to establish whether allergic inflammation changes airway neural sensory reactivity during prolonged allergen exposure. METHODS: Ten nonsmoking patients with birch pollen-allergic asthma performed a capsaicin inhalation challenge twice, once in the off-pollen season and once during the pollen season. The number of coughs and symptoms induced by capsaicin were recorded and compared with those of healthy control subjects. RESULTS: The response to capsaicin, expressed as number of coughs, increased in a dose-dependent manner during both tests. Before the season, the response was similar to that of healthy control subjects, but during the pollen season, the reactivity was significantly increased. Variations in forced expiratory volume in 1 second were not significant before and after each challenge, and values did not change during the pollen season as compared with the winter season. CONCLUSIONS: Sensory reactivity in allergic asthmatic patients may be increased during prolonged allergen exposure as during the pollen season. This finding suggests that allergic inflammation in the lower and/or upper airways may trigger neurogenic mechanisms of significant clinical importance.