Pertussis – Clinical features, Stages, Complications

• Pertussis is caused by the bacterium Bordetella pertussis
• It invades the respiratory tract and causes inflammation and necrosis of surface epithelium resulting in secondary infections
• There are 3 stages in the clinical course of pertussis

Stages of Pertussis

• Catarrhal stage
  • Lasts for about 10 days
  • Insidious onset
  • Lacrimation, coryza, sneezing, mild fever, cough, anorexia and malaise are the features of this stage
• Paroxysmal stage
  • Lasts for 2-4 weeks
  • Bouts of cough followed by an inspiratory crowing sound (whoop) is classically present
  • Apnoea and cyanosis can occur in infants
• Convalescence stage
  • Lasts for 1-2 weeks

Complications:

• Complications tend to occur in infants below 6 months of age
• Commonly seen complications are:
  • Bronchitis
  • Bronchopneumonia
  • Bronchiectasis
• Rare complications:
  • Encephalopathy
• The recurrent bouts of cough can result in:
  • Subconjunctival haemorrhage
  • Epistaxis
  • Haemoptysis
  • Punctate cerebral haemorrhage (can result in convulsions and coma)