What is a characteristic of the paroxysmal stage of pertussis?

The paroxysmal stage of pertussis, also known as whooping cough, is characterized by severe coughing fits that can result in a "whoop" sound as the person inhales after a coughing episode. This stage typically follows the catarrhal stage, during which symptoms resemble those of a common cold, such as runny nose, sneezing, and mild cough.

In the paroxysmal stage, the cough becomes more intense and occurs in bursts or paroxysms, which can be quite distressing and lead to complications such as vomiting, exhaustion, and even brief episodes of apnea, especially in infants. The whooping sound itself is distinctly associated with the disease and occurs due to the effort of trying to inhale against a closed glottis after a series of rapid coughs.

Other symptoms listed, such as fever and chills, are more characteristic of the initial phase of the illness or other respiratory infections and are not the defining features of the paroxysmal stage. Non-stop dry cough may occur, but it does not capture the hallmark "whoop" associated with pertussis. While rhinorrhea and sneezing are common in the early stages, they do not pertain to the paroxys