Etiology
Your Organizational Guidance
ebpracticenet urges you to prioritize the following organizational guidance:
Aanhoudende hoest bij kinderen in de eerste lijnPublished by: Werkgroep Ontwikkeling Richtlijnen Eerste Lijn (Worel)Last published: 2017La toux prolongée chez l’enfant en première ligne de soinsPublished by: Groupe de Travail Développement de recommmandations de première ligneLast published: 2017Upper airway abnormalities are a key component of the syndrome and thus nasal and/or sinus disease is the central causative factor. Seasonal and occupational triggers are recognized risk factors in some people. Other nonspecific triggers of cough include aerosols (e.g., perfumes, air freshener), change in room temperature, air conditioning, and pollen; however, these triggers are not necessarily specific for upper airway cough syndrome (UACS).
Pathophysiology
The pathophysiology is yet to be fully understood. It has been proposed that noxious irritation of the upper airway by either direct physical or chemical irritation results in upregulation of the afferent limb of the cough reflex. This may arise from stimulation of cough receptors located in the hypopharynx or larynx due to secretions translocating from the nose and/or sinuses stimulating the receptors directly. However, the role of nasal discharge in causing chronic cough remains contentious. The fact that some people have troublesome nasal symptoms and copious postnasal drip in the absence of a chronic cough indicates that a more complex interaction and upregulation of neuroregulatory processes may be present.[20]
Many features of UACS overlap with general features of a cough hypersensitivity syndrome (i.e., a clinical syndrome characterized by troublesome coughing often triggered by low levels of thermal, mechanical, or chemical exposure).[7][21] Several features are common to both syndromes, and thus a component of neural hypersensitivity is likely to be present in both.[22] Moreover, it is becoming increasingly apparent that in some patients, chronic cough with UACS may coexist with other clinical features of laryngeal hypersensitivity. This is best conceptualized as an inappropriate or maladaptive response of the glottis (e.g., cough, dysphonia, globus, or inducible laryngeal obstruction presenting with symptoms such as inspiratory stridor or difficulty breathing air into the lungs) to stimuli such as perfumes, various odors, or exercise.[23][24]
The concept of a unified airway has also been proposed as a pathophysiologic factor whereby both the upper and lower airways may be linked by a common local inflammatory process.[25][26] The precise mechanism underpinning this relationship remains to be determined; however, several studies suggest that nasal stimulation (e.g., allergen provocation) in patients with allergic rhinitis may result in increased lower respiratory tract symptoms (e.g., wheeze, dyspnea, cough).[27] Type 2 inflammation in the airways may also link sinonasal disease with cough. Patients with eosinophilic chronic rhinosinusitis often have comorbid asthma or exhibit elevated levels of exhaled nitric oxide, which may present with cough.[28][29]
Use of this content is subject to our disclaimer