Management and diagnosis of psychogenic cough, habit cough, and tic cough: A systematic review

BACKGROUND: Several pharmacologic and nonpharmacologic therapeutic options have been used to treat cough that is not associated with a pulmonary or extrapulmonary etiology.

METHODS: We conducted a systematic review to summarize the evidence supporting different cough management options in adults and children with psychogenic, tic, and habit cough. Medline, EMBASE, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus were searched from the earliest inception of each database to September 2013. Content experts were contacted, and we searched bibliographies of included studies to identify additional references.

RESULTS: A total of 18 uncontrolled studies were identified, enrolling 223 patients (46% male subjects, 96% children and adolescents). Psychogenic cough was the most common descriptive term used (90% of the studies). Most of the patients (95%) had no cough during sleep; barking or honking quality of cough was described in only eight studies. Hypnosis (three studies), suggestion therapy (four studies), and counseling and reassurance (seven studies) were the most commonly used interventions. Hypnosis was effective in resolving cough in 78% of the patients and improving it in another 5%. Suggestion therapy resolved cough successfully in 96% of the patients. The greatest majority of improvements noted with these forms of therapy occurred in the pediatric age group. The quality of evidence is low due to the lack of control groups, the retrospective nature of all the studies, heterogeneity of definitions and diagnostic criteria, and the high likelihood of reporting bias.

CONCLUSIONS: Only low-quality evidence exists to support a particular strategy to define and treat psychogenic, habit, and tic cough. Patient values, preferences, and availability of potential therapies should guide treatment choice.

Somatic Cough Syndrome (Previously Referred to as Psychogenic Cough) and Tic Cough (Previously Referred to as Habit Cough) in Adults and Children: CHEST Guideline and Expert Panel Report

BACKGROUND: We conducted a systematic review on the management of psychogenic cough, habit cough, and tic cough to update the recommendations and suggestions of the 2006 guideline on this topic.

METHODS: We followed the American College of Chest Physicians (CHEST) methodologic guidelines and the Grading of Recommendations, Assessment, Development, and Evaluation framework. The Expert Cough Panel based their recommendations on data from the systematic review, patients' values and preferences, and the clinical context. Final grading was reached by consensus according to Delphi methodology.

RESULTS: The results of the systematic review revealed only low-quality evidence to support how to define or diagnose psychogenic or habit cough with no validated diagnostic criteria. With respect to treatment, low-quality evidence allowed the committee to only suggest therapy for children believed to have psychogenic cough. Such therapy might consist of nonpharmacologic trials of hypnosis or suggestion therapy, or combinations of reassurance, counseling, and referral to a psychologist, psychotherapy, and appropriate psychotropic medications. Based on multiple resources and contemporary psychologic, psychiatric, and neurologic criteria (Diagnostic and Statistical Manual of Mental Disorders, 5th edition and tic disorder guidelines), the committee suggests that the terms psychogenic and habit cough are out of date and inaccurate.

CONCLUSIONS: Compared with the 2006 CHEST Cough Guidelines, the major change in suggestions is that the terms psychogenic and habit cough be abandoned in favor of somatic cough syndrome and tic cough, respectively, even though the evidence to do so at this time is of low quality.

The relationship between chronic cough and paradoxical vocal fold movement: A review of the literature

Chronic cough (CC) and paradoxical vocal fold movement (PVFM) are debilitating conditions. PVFM has been given many labels,(1) including vocal cord dysfunction, Munchausen's stridor, functional inspiratory stridor, nonorganic functional or psychogenic upper airway obstruction, factitious asthma, psychogenic stridor, emotional laryngeal wheezing, and episodic laryngeal dyskinesia. 3 Although CC and PVFM have been considered separate entities in many reports, there is preliminary support for the notion that there may be an underlying link between these two conditions. Speech pathologists have become increasingly involved in the treatment of these patients and therefore need to understand the theoretical background of these disorders, the pathophysiological links between the two, and the impact of voice disorders on these populations. The aim of this article is to review the current literature on CC and PVFM from a speech pathology perspective to provide a model for defining and conceptualizing the disorders and to provide a framework for management and future research.

Efficacy of speech pathology management for chronic cough: a randomised placebo controlled trial of treatment efficacy

Background: Chronic cough that persists despite medical treatment may respond to speech pathology intervention, but the efficacy of such treatment has not been investigated in prospective randomised trials. The aim of this study was to determine the efficacy of a speech pathology intervention programme for chronic cough. Methods: A single blind, randomised, placebo controlled trial was conducted in 87 patients with chronic cough that persisted despite medical treatment. Patients were randomly allocated to receive either a specifically designed speech pathology intervention or a placebo intervention. Participants in both groups attended four intervention sessions with a qualified speech pathologist. Results: Participants in the treatment group had a significant reduction in cough (8.9 to 4.6, p, 0.001), breathing (7.9 to 4.7, p < 0.001), voice (7.3 to 4.6, p < 0.001) upper airway (8.9 to 5.9, p < 0.001) symptom scores and limitation (2.3 to 1.6, p < 0.001) ratings following intervention. There was also a significant reduction in breathing (6.8 to 5.6, p=0.047), cough (7.6 to 6.3, p=0.014), and limitation ( 2.3 to 2.0, p=0.038) scores in the placebo group, but the degree of improvement was significantly less than in the treatment group (p < 0.01). Clinical judgement of outcome indicated successful ratings in 88% of participants in the treatment group compared with 14% in the placebo group ( p, 0.001). Conclusion: Speech pathology is an effective management intervention for chronic cough which may be a viable alternative for patients who do not respond to medical treatment.

Cough-generated aerosols of Pseudomonas aeruginosa and other Gram Negative Bacteria from cystic fibrosis patients.

Background: Pseudomonas aeruginosa is the most common bacterial pathogen in cystic fibrosis (CF) patients. Current infection control guidelines aim to prevent transmission via contact and respiratory droplet routes and do not consider the possibility of airborne transmission. We hypothesized that with coughing, CF subjects produce viable, respirable bacterial aerosols. Methods: Cross-sectional study of 15 children and 13 adults with CF, 26 chronically infected with P. aeruginosa. A cough aerosol sampling system enabled fractioning of respiratory particles of different size, and culture of viable Gram negative non-fermentative bacteria. We collected cough aerosols during 5 minutes voluntary coughing and during a sputum induction procedure when tolerated. Standardized quantitative culture and genotyping techniques were used. Results: P. aeruginosa was isolated in cough aerosols of 25 (89%) subjects of whom 22 produced sputum samples. P. aeruginosa from sputum and paired cough aerosols were indistinguishable by molecular typing. In 4 cases the same genotype was isolated from ambient room air. Approximately 70% of viable aerosols collected during voluntary coughing were of particles ≤ 3.3 microns aerodynamic diameter. P. aeruginosa, Burkholderia cenocepacia Stenotrophomonas maltophilia and Achromobacter xylosoxidans were cultivated from respiratory particles in this size range. Positive room air samples were associated with high total counts in cough aerosols (P=0.003). The magnitude of cough aerosols were associated with higher FEV1 (r=0.45, P=0.02) and higher quantitative sputum culture results (r=0.58, P=0.008). Conclusion: During coughing, CF patients produce viable aerosols of P. aeruginosa and other Gram negative bacteria of respirable size range, suggesting the potential for airborne transmission.

Size and habit of mineral particles in bone and mineralized callus during bone healing in sheep

Bone healing is known to occur through the successive formation and resorption of various tissues with different structural and mechanical properties. To get a better insight into this sequence of events, we used environmental scanning electron microscopy (ESEM) together with scanning small-angle X-ray scattering (sSAXS) to reveal the size and orientation of bone mineral particles within the regenerating callus tissues at different healing stages (2, 3, 6, and 9 weeks). Sections of 200 µm were cut from embedded blocks of midshaft tibial samples in a sheep osteotomy model with an external fixator. Regions of interest on the medial side of the proximal fragment were chosen to be the periosteal callus, middle callus, intercortical callus, and cortex. Mean thickness (T parameter), degree of alignment (ρ parameter), and predominant orientation (ψ parameter) of mineral particles were deduced from resulting sSAXS patterns with a spatial resolution of 200 µm. 2D maps of T and ρ overlapping with ESEM images revealed that the callus formation occurred in two waves of bone formation, whereby a highly disordered mineralized tissue was deposited first, followed by a bony tissue with more lamellar appearance in the ESEM and where the mineral particles were more aligned, as revealed by sSAXS. As a consequence, degree of alignment and mineral particle size within the callus increased with healing time, whereas at any given moment there were structural gradients, for example, from periosteal toward the middle callus.

Development of a children's acute cough specific quality of life questionnaire (Pac-Qol)

The high burden of parental concern in children with chronic cough has been well documented. Acute cough in children (lasting less than 2 weeks) also has a significant impact on families, reflected by the number of doctor visits for cough. Currently there is no validated acute cough specific quality of life (QOL) measure for children. The objective of this study is to develop and validate an acute cough specific QOL questionnaire (PAC-QOL) for paediatric use. Here we present our data on item selection. Methods Two independent focus groups were conducted to determine relevant items. Parents discussed the impact of their child’s current or previous episodes of acute cough on their child, themselves and their family functioning. Transcripts were analyzed to determine whether discussions had reached an item saturation point. Items were also compared against our previously validated parent-centred children’s chronic cough specific QOL questionnaire (PC-QOL), which was used as a model. The newly developed acute cough specific QOL questionnaire is designed to assess the level of frequency of parents’ feelings and worry related to their child’s acute cough, using a 24-h time-point reference. Results Newly identified acute cough specific items include parental worry around whether or not they should take their child to a doctor or emergency department, and frequency of seeking assistance from friends and family. Conclusions While there are similarities between items identified for both acute and chronic cough, there are distinct features. Further data will be collected for item reduction and validation of this children’s acute cough specific QOL questionnaire.

Defining the parental burden of acute cough in children

Despite the prevalence of acute cough in children (<2 weeks duration), the burden to parents and families is largely unknown. The objectives of this study were to determine the parental burden of children’s acute cough, and to evaluate psychological and other infl uences on the reported burden of acute cough in children. Methods Parents of children with a current acute cough (<2 weeks) at enrolment completed 4 questionnaires (state trait anxiety inventory (STAI); short form health survey (SF-8); depression, anxiety and stress 21-item scale (DASS21); and our preliminary 48-item parent acute cough specifi c quality of life (PAC-QOL48) questionnaire). In PAC-QOL48, lower scores refl ect worse QOL. Results Median age of the 104 children enrolled was 2.63 (IQR 1.42, 4.79) years, 54 were boys. Median length of cough at enrolment was 3 (IQR 2, 5) days. Median total PAC-QOL48 score of parents enrolled at presentation to the emergency department (n = 70) was signifi cantly worse than of parents enrolled through the community (n = 24) (p < 0.01). More than half (n = 55) had sought medical assistance more than once for the current acute coughing illness. PAC-QOL48 score was signifi cantly negatively correlated to verbal category descriptive and visual analogue scale cough scores (Spearman r = −0.26, p = 0.05 and r = −0.46, p = 0.01 respectively) and DASS21 total score (r = −0.36, p = 0.01), but not to child’s age. Conclusions Consistent with data on chronic cough, stress was the predominant factor of parental burden. This study highlights the ongoing need for clinicians to be cognizant of parental worries and concerns when their children are coughing, and for further research into safe and effective therapies for acute cough in children.

The development of chronic cough in children following presentation to a tertiary paediatric emergency department with acute respiratory illness : study protocol for a prospective cohort study

Background Acute respiratory illness, a leading cause of cough in children, accounts for a substantial proportion of childhood morbidity and mortality worldwide. In some children acute cough progresses to chronic cough (> 4 weeks duration), impacting on morbidity and decreasing quality of life. Despite the importance of chronic cough as a cause of substantial childhood morbidity and associated economic, family and social costs, data on the prevalence, predictors, aetiology and natural history of the symptom are scarce. This study aims to comprehensively describe the epidemiology, aetiology and outcomes of cough during and after acute respiratory illness in children presenting to a tertiary paediatric emergency department. Methods/design A prospective cohort study of children aged <15 years attending the Royal Children's Hospital Emergency Department, Brisbane, for a respiratory illness that includes parent reported cough (wet or dry) as a symptom. The primary objective is to determine the prevalence and predictors of chronic cough (>= 4 weeks duration) post presentation with acute respiratory illness. Demographic, epidemiological, risk factor, microbiological and clinical data are completed at enrolment. Subjects complete daily cough dairies and weekly follow-up contacts for 28(+/-3) days to ascertain cough persistence. Children who continue to cough for 28 days post enrolment are referred to a paediatric respiratory physician for review. Primary analysis will be the proportion of children with persistent cough at day 28(+/-3). Multivariate analyses will be performed to evaluate variables independently associated with chronic cough at day 28(+/-3). Discussion Our protocol will be the first to comprehensively describe the natural history, epidemiology, aetiology and outcomes of cough during and after acute respiratory illness in children. The results will contribute to studies leading to the development of evidence-based clinical guidelines to improve the early detection and management of chronic cough in children during and after acute respiratory illness.

Cough formation in viral infections in children

Using a multidisciplinary approach, Human Respiratory Viral Infections is set at the level between the definitive reference work and an essential clinical manual. Exploring recent advances in human respiratory viral research, the text builds on the basic sciences of epidemiology, virology, molecular biology, and immunology to cover clinical diagnosis, mechanism of pathogenesis, manifestations of disease, impact, treatment, and management strategies.

Do sex and atopy influence cough outcome measurements in children?

Background Despite the commonality of cough and its burden, there are no published data on the relationship between atopy or sex on objectively measured cough frequency or subjective cough scores in children. In 202 children with and without cough, we determined the effect of sex and atopy on validated cough outcome measurements (cough receptor sensitivity [CRS], objective cough counts, and cough scores). We hypothesized that in contrast to adult data, sex does not influence cough outcome measures, and atopy is not a determinant of these cough measurements. Methods We combined data from four previous studies. Atopy (skin prick test), the concentration of capsaicin causing two and five or more coughs (C2 and C5, respectively), objectively measured cough frequency, and cough scores were determined and their relationship explored. The children’s (93 girls, 109 boys) mean age was 10.6 years (SD 2.9), and 56% had atopy. Results In multivariate analysis, CRS was influenced by age (C2 coefficient, 5.9; P = .034; C5 coefficient, 29.1; P = .0001). Atopy and sex did not significantly influence any of the cough outcomes (cough counts, C2, C5, cough score) in control subjects and children with cough. Conclusions Atopy does not influence important cough outcome measures in children with and without chronic cough. However, age, but not sex, influences CRS in children. Unlike adult data, sex does not affect objective counts or cough score in children with and without chronic cough. Studies on cough in children should be age matched, but matching for atopic status and sex is less important.

An objective study of acid reflux and cough in children using an ambulatory pHmetry-cough logger

Objective There are no objective ambulatory studies on the temporal relationship between reflux and cough in children. Commercial pHmetry loggers have slow capture rates (0.25 Hz) that limit objective quantification of reflux and cough. The authors aimed to evaluate if there is a temporal association between cough and acid pH in ambulatory children with chronic cough. setting and patients The authors studied children (aged <14 years) with chronic cough, suspected of acid reflux and considered for pHmetry using a specifically built ambulatory pHmetry–cough logger that enabled the simultaneous ambulatory recording of cough and pH with a fast (10 Hz) capture rate. Main outcome measures Coughs within (before and after) 10, 30, 60 and 120 s of a reflux episode (pH<4 for >0.5 s). Results Analysis of 5628 coughs in 20 children. Most coughs (83.9%) were independent of a reflux event. Cough–reflux (median 19, IQR 3–45) and reflux–cough (24.5, 13–51) sequences were equally likely to occur within 120 s. Within the 10 and 30 s time frame, reflux–cough (10 s=median 2.5, IQR 0–7.25; 30 s=6.5, 1.25–22.25) sequences were significantly less frequent than reflux–no cough (10 s=27, IQR 15–65; 30 s=24.5, 14.5–55.5) sequences, (p=0.0001 and p=0.001, respectively). No differences were found for 60 and 120 s time frame. Cough–reflux sequence (median 1.0, IQR 0–8) within 10 s was significantly less (p=0.0001) than no cough–reflux sequences (median 29.5, 15–67), within 30 s (p=0.006) and 60 s (p=0.048) but not within 120 s (p=0.47). Conclusions In children with chronic cough and suspected of having gastro-oesophageal reflux disease, the temporal relationship between acid reflux and cough is unlikely causal.

Validation of a parent-proxy quality of life questionnaire for paediatric chronic cough (PC-QOL)

Background Quality of life (QOL) measures are an important patient-relevant outcome measure for clinical studies. Currently there is no fully validated cough-specific QOL measure for paediatrics. The objective of this study was to validate a cough-specific QOL questionnaire for paediatric use. Method 43 children (28 males, 15 females; median age 29 months, IQR 20–41 months) newly referred for chronic cough participated. One parent of each child completed the 27-item Parent Cough-Specific QOL questionnaire (PC-QOL), and the generic child (Pediatric QOL Inventory 4.0 (PedsQL)) and parent QOL questionnaires (SF-12) and two cough-related measures (visual analogue score and verbal category descriptive score) on two occasions separated by 2–3 weeks. Cough counts were also objectively measured on both occasions. Results Internal consistency for both the domains and total PC-QOL at both test times was excellent (Cronbach alpha range 0.70–0.97). Evidence for repeatability and criterion validity was established, with significant correlations over time and significant relationships with the cough measures. The PC-QOL was sensitive to change across the test times and these changes were significantly related to changes in cough measures (PC-QOL with: verbal category descriptive score, rs=−0.37, p=0.016; visual analogue score, rs=−0.47, p=0.003). Significant correlations of the difference scores for the social domain of the PC-QOL and the domain and total scores of the PedsQL were also noted (rs=0.46, p=0.034). Conclusion The PC-QOL is a reliable and valid outcome measure that assesses QOL related to childhood cough at a given time point and measures changes in cough-specific QOL over time.