WHOOPING COUGH

Pertussis

An acute bacterial respiratory infection characterised by an inspiratory whoop following paroxysmal cough. It is highly contagious with an incubation period of 7-10 days. It is a notifiable disease.

Cause

  • Bordetella pertussis, spread by droplet infection

Clinical features

Stage 1: Coryzal (catarrhal: 1-2 weeks)

  • Most infectious stage
  • Running nose, mild cough, slight fever

Stage 2: Paroxysmal (1-6 weeks)

  • More severe and frequent repetitive cough ending in a whoop, vomiting, conjuctival haemorrhage
  • Fever may be present; patient becomes increasingly tired
  • In infants <6 months: paroxyms lead to apnoea, cyanosis (coughing bouts and whoops may be absent)

Stage 3: Convalescent

  • Paroxysmal symptoms reduce over weeks or months
  • Cough may persist

Complications may include

  • Respiratory: pneumonia (new onset fever a symptom), atelectasis, emphysema, bronchiectasis, otitis media
  • Nervous system: convulsions, coma, intracranial haemorrhage
  • Others: malnutrition, dehydration, inguinal hernia, rectal prolapse

Differential diagnosis

  • Chlamydial and bacterial respiratory tract infection
  • Foreign body in the trachea

Investigations

  • Clinical diagnosis
  • Blood: complete blood count
  • Chest X-ray

Management

  • Maintain nutrition and fluids
  • Give oxygen and perform suction if the child is cyanotic
  • For the unimmunised or partly immunised, give DPT (three doses) as per routine immunisation
    schedule
  • Isolate the patient (avoid contact with other infants) until after 5 days of antibiotic treatment
  • Treatment should be initiated within 3 weeks from onset of cough: Erythromycin 500 mg every
    6 hours for 7 days
    Child: 10-15 mg/kg every 6 hours
Note
  • Cough mixtures, sedatives, mucolytics, and antihistamines are USELESS in pertussis and should
    NOT be given

Prevention

  • Educate parents on the importance of following the routine childhood immunisation schedule
  • Ensure good nutrition
  • Avoid overcrowding
  • Booster doses of vaccine in exposed infants