[Mechanisms responsible for coughing in patients with rhinitis]

Mechanisms responsible for coughing in patients with rhinitis are not completely elucidated, because afferent innervation of nasal mucosa is not able to mediate cough reflex. There are several mechanisms that can participate in this pathogenetic process. The group of these mechanisms include: postnasal dripping of nasal mucus into the larynx, complete obstruction of the nasal cavity with inappropriate air conditioning, incomplete obstruction of nasal cavity with a possibility of microaspiration of nasal exudate, nasobronchial reflex, facilitating interaction between afferent inputs from nasal mucosa and central neuronal network responsible for coughing or propagation of the inflammatory process from the nose via airways or via systemic circulation into the lower airways mucosa. The most important mechanism that should be taken into consideration is hightened cough sensitivity (decreased threshold of afferent nerve endings in the larynx, trachea and more peripheral airways mediating cough) due to different effects of mechanisms mentioned above on the structure and/or function of afferent nerve endings in the lower airways responsible for inception and modulation of the cough reflex.