Diagnosis and therapy of chronic cough

Abstract

A cough that lasts for more than 8 weeks in adults (those older than 15 years) and more than 4 weeks in children is considered chronic and poses a significant health problem, as it can lead to feelings of fatigue, sleep disturbances, hoarseness, disruption of daily activities, vomiting, and often in women, even incontinence. The differential diagnosis of chronic cough in adults and children has its specificities. In certain cases, the etiological factor remains unknown when referring to unexplained (idiopathic) chronic cough. This paper presents the results of a systematic review of publications in medical databases (PubMed) and guidelines from the European Respiratory Society (ERS) and the American College of Chest Physicians (CHEST), related to the diagnosis and treatment of chronic cough. Diagnostic investigations should be focused on the most common causes of chronic cough. In adults, these include asthma, chronic obstructive pulmonary disease, bronchiectasis, interstitial lung disease, lung malignancy, non-asthmatic eosinophilic bronchitis, gastroesophageal reflux disease, and upper airway cough syndrome. In children, the most common causes of chronic cough are asthma, protracted bacterial bronchitis, cystic fibrosis, primary ciliary dyskinesia, bronchiectasis, tracheobronchomalacia, pertussis, habitual (psychogenic) cough, and foreign body aspiration. The treatment primarily involves excluding medications that might have chronic cough as an adverse effect. Therapy is directed toward treating the underlying cause of chronic cough. If the cough persists despite treatment (refractory cough) or if it's idiopathic, neuromodulatory medications are employed (opioids, gamma-aminobutyric acid analogs, tricyclic antidepressants). Therapeutic options also include breathing and vocal techniques, superior laryngeal nerve blocks, and vocal cord medialization injections. Drugs directly inhibiting sensory receptors (P2X3, TRPV-1, and NK-1 inhibitors) are currently under clinical trial investigation. The use of validated tests is crucial for assessing therapeutic effectiveness. The etiological factors of chronic cough can have both infectious and non-infectious origins and are not always related to lung diseases. Considering that chronic cough is regarded as a condition of hypersensitivity, when causal treatment does not yield satisfactory results or when dealing with idiopathic chronic cough, therapy is directed towards central or peripheral neuromodulation, as well as techniques involving breathing and vocal production.