AKT · Child health/Infection & rash

Whooping cough

Bordetella pertussis

Overview

A notifiable respiratory infection (Bordetella pertussis) with paroxysmal coughing fits, an inspiratory "whoop", and post-tussive vomiting. Dangerous (apnoea) in unimmunised infants; prevented by maternal antenatal vaccination.

Recognise

Catarrhal phase (coryza) → paroxysmal phase: coughing fits + inspiratory WHOOP + post-tussive vomiting
Apnoea in young infants (may have no whoop)
Cough persists for weeks ("100-day cough")

Red flags

Apnoea/cyanosis in an infant; feeding difficulty → admit

Differentials & how to tell them apart

Bronchiolitiswheeze + crackles, RSV, no whoop/post-tussive vomiting

Viral URTIno paroxysms/whoop

Foreign bodysudden onset, focal signs

Investigations

Per nasal swab culture/PCR (early); anti-pertussis toxin serology / oral fluid (later). Lymphocytosis on FBC. NOTIFIABLE.

Management

Macrolide (azithromycin/clarithromycin) if within 21 days of cough onset

1Notify (notifiable). Macrolide antibiotic if started within 21 days of onset — limits transmission (may not shorten cough).Gate: After 21 days of cough, antibiotics are not generally recommended (not infectious / no benefit) — treat supportively
2Admit infants with apnoea/cyanosis/feeding difficulty. Exclude from school until 48h of antibiotics (or 21 days from onset).

Macrolide — azithromycin/clarithromycin (erythromycin in pregnancy) — within 21 days of onset

Antibiotic prophylaxis — for close vulnerable contacts

Key points

Maternal antenatal pertussis vaccination protects newborns. The infant may present with APNOEA and no classic whoop.

Monitor & prognosis

Apnoea, feeding, complications (pneumonia, seizures).

Prolonged cough; serious in young infants.

Source: NICE CKS Whooping cough; UKHSA