Whooping Cough

Question 1

Outline the pathophysiology of whooping cough

Answer 1

Bordetella pertussis = gram -ve

Spread = aerosolised droplets

Bacteria attach to the resp ep, produce toxins which paralyse cilla, promote inflam, impairing clearance of resp secretions leading to cough

Question 2

When is the whooping cough vaccine given?

Answer 2

2, 3, 4 months

Booster at 3 years + 4 months

Question 3

How does whooping cough present?

Answer 3

Catarrhal Phase (1-2w)

• rhinitis
• conjunctivitis
• irritability
• sore throat
• low grade fever
• dry cough

Paroxysmal phase (2-8w)

• severe paroxysms of coughing followed by an inspiratory gasp, producing the classic ‘whoop’
• <3m whoop is less common, apnoea is more common
• cough is more common at night, followed by vomiting, maybe cyanosis

Question 4

Outline a DDx for a child presenting with paroxysmal cough

Answer 4

Bronchiolitis = wheeze, <1y, acute

Mycoplasma pneumonia = wheeze, crackles, normal WBC, nasopharyngeal PCR confirmation

Bacterial pneumonia = focal crackles, pyrexia

Asthma = chronic night cough, breathlessness, wheeze, atopy FH

TB = chronic cough, growth failure/weight loss, contact/travel Hx

Question 5

How should suspected whooping cough be Ix?

Answer 5

Cough <2w = culture nasopharyngeal aspirate

Cough >2w

• <5y = anti-pertussis toxin IgG serology
• 5-17y = anti-pertussis toxin in oral fluid

Question 6

How should whooping cough be Mx?

Answer 6

Admit if =

• <6m and acutely unwell
• significant breathing diff
• feeding diff
• significant complications (seizures, pneumonia)

Cough <21d = macrolide

• <1m = clarithromycin
• > 1m = azithromycin

Supportive = paracetamol, ibuprofen

Inform parents: cough may take 3m to resolve

Question 7

Name the possible complications of whooping cough

Answer 7

Secondary bacterial pneumonia (20%)

Seizures

Encephalopathy

Otitis media

Mortality = 3.5% in <6m, 0.03% in >6m