Symptoms & Signs
The clinical course of the disease comprises of three stages, the catarrhal, the paroxysmal and the convalescent stage.
The catarrhal stage: lasts for about 1-2 weeks. The patient may experience general symptoms of mild cough, low grade fever, weakness, runny nose and sore eyes. This is a highly infectious stage, which closely resembles common cold.
The paroxysmal stage: lasts for around 2-4 weeks with the characteristic violent, sudden and repetitive uncontrolled coughing or the “paroxysms” of coughing with inspirations between the coughs. The distinctive whooping sound usually seen in the children is because of the sudden inspiration of air against the closed glottis (opening between the vocal cords at the upper part of the larynx) at the end of the paroxysm. Vomiting precedes the coughing episode. There is also violent coughing at night during sleep. Most of the complications of pertussis develop during this stage.
The convalescent stage: there is a gradual reduction of the cough in intensity but it takes months to be completely resolved. There can be a reoccurrence of the paroxysmal coughing due to additional infections by bacteria or viruses with the development of fever.
In adults and adolescents, the cough may be with or without paroxysms and could occur for over 2 weeks. Whooping is less common in adults because the air passages are wider but there is usually a shortness of breath during the coughing spell, irritation in the throat with vomiting after the coughing episode.
