Postinfectious Cough: Pathogenesis
On the other hand, with upper respiratory infections of undetermined cause that produce a persistent cough, it has been shown that there is an increased sensitivity to inhaled capsaicin during the acute phase of the illness. When tested during convalescence at 4 weeks and beyond, cough sensitivity returns to baseline.
Therefore, transient inflammation of the lower airways is likely to be important in the pathogenesis in some patients with postinfectious cough. This speculation is based on the fact that cough may be induced by the heightened responsiveness of the cough receptors, by bronchial hyperresponsiveness as is seen in cough-variant asthma, or by impaired mucociliary clearance from the disruption of the epithelial lining of the airways. asthma inhaler
Because airway inflammation causes mucus hypersecretion, retained secretions resulting from excessive mucus production and decreased clearance may be another important mechanism of cough. Additionally, persistent inflammation of the upper airway, particularly the nose and paranasal sinuses, can be the cause of or can contribute to postinfectious cough. When secretions drain into the hypopharynx and larynx or when there is inflammation of the upper airway, cough receptors can be stimulated, and this may persist for weeks or longer following an upper respiratory in-fection. Another mechanism to consider in postin-fectious cough is gastroesophageal reflux. Although viral infection itself does not cause gastroesophageal reflux disease, the vigorous coughing that follows may induce or aggravate preexisting reflux disease because of the high abdominal pressures that are generated. Patients with the subacute postinfectious cough are therefore similar to those with chronic cough. The pathogenesis is frequently multifactorial.
Category: Respiratory Symptoms
Tags: Bordetella pertussis, pertussis infection, postinfectious cough, postviral cough