Cough in Children and Adults: Diagnosis, Assessment and Management (CICADA). Summary of an updated position statement on chronic cough in Australia

[Specialist Guidelines of The German Respiratory Society for Diagnosis and Treatment of adult Patients Suffering from Cough]

This is the 4th edition of the Cough Guidelines of the German Respiratory Society written by respiratory, gastroenterology, ear-nose-throat specialists, including respiratory physiotherapists and speech pathology specialists; importantly, a patient representative was also involved.Compared with earlier versions we used a new methodology: after discussion in the guidelines group, we asked and answered the 12 most important and most frequent "key" questions regarding the clinical practice. The extent of the guideline could thus be significantly reduced.We added a short scientific background to each of the answers including the most recent references. The recommendations and statements were created in consensus and graded as strong, or weak. If sufficient literature was not available, we suggested discussing joint decisions with the patient.The 12 key questions are as follows:- Key question 1: The classification of cough (acute, i. e. up to three weeks duration; chronic, i. e. after 8 weeks duration and subacute in between) did not change, but we added "cough with or without expectoration as an additional classification aspect with therapeutic consequences.- Key question 2: Acute and subacute cough are mostly (but not exclusively) due to the common cold. They are the first or second most frequent symptom prompting patients to seek medical (or pharmacist's) care. Antibiotic therapy is strongly discouraged for common cold- Key question 3: We defined "Red flags" for mandatory immediate diagnostic for acute cough, which usually does not require such diagnostic procedures- Key question 4: Chronic cough overview of the most common causes for- Key question 5: Cough in acute SARS-CoV-2 infection and in long COVID - Key question 6: Refractory chronic cough and idiopathic chronic cough, two recently established entities were explained more in detail- Key question 7: To upper airway cough syndrome - Key question 8: Gastro-oesophageal-reflux-related cough - Key question 9: Cough-variant asthma and non-asthmatic eosinophilic bronchitis - Key question 10: Overview of drugs causing cough - Key question 11: Basic and personalized (due to the individual history) diagnostic procedures for patients with cough- Key question 12: Physiotherapy, speech therapy and pharmacotherapy for cough.

WAO - ARIA consensus on chronic cough: Executive summary

Acute cough is a highly prevalent symptom in clinical practice. Chronic cough is a complex disease with significant impact on quality of life. The mechanistic pathways of chronic cough in cough-comorbid clinical phenotypes are elusive. Mounting evidence suggests presence of a hypersensitive cough reflex and implication of transient receptor potential channels and P2X receptors in cough neuronal pathways. Previously, the World Allergy Organization (WAO)/Allergic Rhinitis and its Impact on Asthma (ARIA) Joint Committee on Chronic Cough published updated experimental and clinical data on chronic cough, in addition to a multidisciplinary care pathway approach to its management. The goal of this manuscript is to provide clinicians with a succinct summary of chronic cough pathophysiology, clinical phenotypes, and management strategies in both primary and cough specialty care. This executive summary is a primer for clinicians on chronic cough. Increasing awareness on the topic among primary care physicians will improve the outcome of management of patients with chronic cough.

Nonpharmacological Approaches to Chronic Cough

Although cough is a protective reflex, it can occur in the absence of any physical need to clear the airway. In chronic cough, cough can be triggered by innocuous stimuli and persist despite medical treatment. Nonpharmacological interventions such as cough control therapy, provided by speech pathologists, have gained popularity in recent years. Intervention targets refractory or unexplained chronic cough, and efficacy has been studied in randomized controlled trials. Key elements of cough control therapy include education, anticipation, and control of the urge to cough, reducing laryngeal irritation and psychoeducational counseling. Our understanding of the mechanisms behind the success of nonpharmacological treatment is developing. It is likely the mechanisms of action are multifactorial across peripheral, central, and higher cortical regions. Nonpharmacological cough control therapy interventions are now included in international cough guidelines. However, approach to service delivery is not standardized and varies between regions and countries.

Current opinion in refractory and/or unexplained chronic cough

PURPOSE OF REVIEW

Otolaryngologists are vital to successfully managing chronic cough in adults. This review presents updates regarding rapidly evolving concepts in chronic cough.

RECENT FINDINGS

Significant growth is occurring in chronic cough research, strengthening the evidence of its major psychosocial impacts. Elucidation of the neural underpinnings of normal and abnormal cough within both the peripheral and central nervous systems highlight the previously underappreciated complexity of cough. Recent clinical practice recommendations emphasize personalized treatment approaches through addressing treatable traits of chronic cough. Investigations are ongoing to better distinguish chronic cough subgroups, and multiple types of important clinical outcome measures are being characterized. Newer research about chronic cough treatment encompasses pharmacologic and nonpharmacologic interventions, including oral and inhaled medications, superior laryngeal nerve blocks, and behavioral therapy.

SUMMARY

As knowledge about chronic cough in adults continues to expand in both research and clinical practice, otolaryngologists can continue to raise awareness of the role of the larynx in cough and promote ongoing multidisciplinary collaborations. In the coming years, more pharmacologic options and personalized treatment approaches will likely emerge for chronic cough.

Chronic cough as a disease

Chronic cough is a frequent reason for medical consultation and has significant impact on quality of life. Due to the limited effectiveness of currently available treatments, and delays in accessing care, patients are often inadequately managed. There remains an overreliance by clinicians on outdated management algorithms, addressing chronic cough only as symptom of other medical conditions, and advocating investigation and trials of treatment of diseases which are often not present. This may lead to unnecessary cost, frustration and potential harm. Newer clinical guidelines in essence consider chronic cough as a disease in itself, resulting from afferent neuronal hypersensitivity and central nervous system dysfunction. Secondary factors which aggravate chronic cough (smoking, asthma, gastro-oesophageal reflux, etc.) are better considered as treatable traits associated with the primary disease process rather than direct "causes" of cough. Explicitly approaching chronic cough as a discrete entity is consistent with the way in which "diseases" are generally characterised, and has advantages. The patient should be better able to understand their condition, and may have better confidence in attempts at management. The clinician should have better focus and avoid unfruitful treatments and investigation. In general, considering chronic cough as a disease should help to raise the profile of the condition, improve organisation of health service pathways, increase attention for research, and further the development of new treatments.

Role of Spirometry, Radiology, and Flexible Bronchoscopy in Assessing Chronic Cough in Children

Chronic cough in children is a common and multifaceted symptom, often requiring a comprehensive approach for accurate diagnosis and effective management. This review explores the use of spirometry, radiology (chest X-rays and computed tomography (CT) scans), and flexible bronchoscopy in the assessment of chronic cough in children through current guidelines and studies. The strengths, clinical indications, and limitations of each modality are examined. Spirometry, radiology, and in some cases flexible bronchoscopy are integral to the assessment of chronic cough in children; however, a tailored approach, leveraging the strengths of each modality and guided by clinical indications, enhances diagnostic accuracy and therapeutic outcomes of pediatric chronic cough.

Cough in Protracted Bacterial Bronchitis and Bronchiectasis

Chronic cough in children is a common condition for which patients seek medical attention, and there are many etiologies. Of the various causes of chronic cough in children, protracted bacterial bronchitis (PBB) is one of the commonest causes, and bronchiectasis is one of the most serious. Together, they lie on different ends of the spectrum of chronic wet cough in children. Cough is often the only symptom present in children with PBB and bronchiectasis. This review highlights the role of cough as a marker for the presence of these conditions, as well as an outcome endpoint for treatment and research.

Chronic Bronchitis in Children and Adults: Definitions, Pathophysiology, Prevalence, Risk Factors, and Consequences

The complex nature of chronic bronchitis (CB) and changing definitions have contributed to challenges in understanding its aetiology and burden. In children, CB is characterised by persistent airway inflammation often linked to bacterial infections and is therefore termed "protracted bacterial bronchitis" (PBB). Longitudinal studies suggest that CB in childhood persists into adulthood in a subgroup. It can also be associated with future chronic respiratory diseases including asthma, bronchiectasis, and chronic obstructive pulmonary disease (COPD). Adult CB is traditionally associated with smoking, occupational exposures, and lower socioeconomic status. The interplay between risk factors, childhood CB, adult CB, and other chronic respiratory diseases is intricate, requiring comprehensive longitudinal studies for a clearer understanding of the natural history of CB across the lifespan. Such longitudinal studies have been scarce to date given the logistic challenges of maintaining them over time. In this review, we summarise current evidence on the evolution of the definitions, pathophysiology, risk factors, and consequences of childhood and adulthood chronic bronchitis.