What are the symptoms of pertussis?

Symptoms of Pertussis (Whooping Cough)

Pertussis presents with a characteristic progression through three distinct stages: catarrhal, paroxysmal, and convalescent, with the hallmark symptom being paroxysmal coughing fits often followed by an inspiratory "whoop" and posttussive vomiting. 1, 2

Stages of Pertussis Infection

1. Catarrhal Stage (1-2 weeks)

• Insidious onset with symptoms indistinguishable from minor respiratory infections:
  • Nasal congestion and runny nose
  • Mild sore throat
  • Mild dry cough
  • Minimal or no fever
  • Conjunctivitis
  • Malaise 1, 2

2. Paroxysmal Stage (4-6 weeks)

• Characterized by severe coughing episodes:
  • Paroxysmal cough - succession of coughs without inspiration
  • Inspiratory "whoop" (classic sound when gasping for breath)
  • Posttussive vomiting
  • Cyanosis during coughing episodes
  • Exhaustion after coughing episodes
  • Increased frequency and severity of cough as illness progresses
  • More frequent paroxysms at night
  • Patients appear relatively well between episodes 1

3. Convalescent Stage (2-6 weeks or longer)

• Gradual recovery:
  • Decreasing frequency of coughing bouts
  • Persistent non-paroxysmal cough
  • Possible recurrence of paroxysms with superimposed viral infections 1

Age-Specific Presentation

Infants

• May present with atypical disease:
  • Apneic spells
  • Minimal cough
  • Absent classic "whoop"
  • Higher risk of severe complications and death 1, 2

Adults and Previously Vaccinated Individuals

• Often milder illness
• Classic "whoop" frequently absent
• May present with prolonged cough as the only symptom
• Shortness of breath and tingling sensation in throat
• Some adults may be asymptomatic despite infection 1

Common Complications

Infants and Young Children

• Apnea
• Pneumonia
• Seizures
• Death 3

Adolescents and Adults

• Complications from severe coughing:
  • Pneumothorax (up to 5%)
  • Rib fracture (up to 4%)
  • Epistaxis (nosebleeds)
  • Subconjunctival hemorrhage
  • Subdural hematoma
  • Hernia
  • Rectal prolapse
  • Urinary incontinence (common in women)
  • Loss of consciousness/cough syncope (up to 3-6%)
  • Weight loss
  • Sleep disturbance 1, 4, 5

Important Clinical Considerations

• Patients are most infectious during the catarrhal stage and first 3 weeks after cough onset 1
• The disease is highly contagious with secondary attack rates exceeding 80% among susceptible contacts 1
• Symptoms may persist for months in some cases 1
• Pertussis should be considered in any patient with cough lasting >2 weeks without another apparent cause, especially when accompanied by paroxysms, posttussive vomiting, or inspiratory whoop 1
• Adults with pertussis often make multiple healthcare visits before diagnosis is considered 1

Diagnostic Pitfalls

• Pertussis is frequently overlooked in adolescents and adults due to atypical presentation 4
• Leukocytosis and lymphocytosis, traditionally associated with pertussis, may not be present in all cases 1
• Symptoms can mimic other respiratory conditions, leading to delayed diagnosis 1
• Early antibiotic treatment (before cough onset) may modify the clinical expression of the disease 1

Early recognition of pertussis symptoms is crucial for prompt treatment to reduce transmission, even though antibiotics may not significantly alter the course of illness once the cough has begun 2, 6.