AKT · Child health/Infection & rash

Croup

Parainfluenza virus

Overview

Laryngotracheobronchitis (usually parainfluenza) in 6 months–6 years, causing a BARKING cough, stridor and hoarseness, typically worse at night. A single dose of oral dexamethasone is the cornerstone.

Recognise

BARKING ("seal-like") cough, inspiratory stridor, hoarse voice
Coryzal prodrome, low-grade fever, worse at night
Stridor at rest = more severe

Red flags

Severe: stridor at rest, marked recession, agitation/drowsiness, cyanosis → admit

Differentials & how to tell them apart

Acute epiglottitis (Hib)rapid, toxic, DROOLING, tripod, soft stridor, NO barking cough — do not examine throat

Inhaled foreign bodysudden onset, choking episode, unilateral signs

Bacterial tracheitistoxic, high fever, poor steroid response

Anaphylaxisurticaria, exposure, rapid

Investigations

Clinical diagnosis. Do NOT examine the throat if epiglottitis is a possibility. Avoid distressing the child.

Management

Oral dexamethasone 0.15 mg/kg single dose

1Give a single dose of oral dexamethasone 0.15 mg/kg to ALL children with croup, even mild.Gate: If too unwell to take oral → nebulised budesonide 2 mg or IM dexamethasone 0.6 mg/kg
2Moderate/severe (stridor at rest): admit; nebulised adrenaline for severe distress (effect is temporary — observe for rebound).

Dexamethasone — oral 0.15 mg/kg single dose — first-line for ALL severities

Nebulised adrenaline — severe croup (temporary), with steroid

Budesonide (nebulised) — if oral not tolerated

Key points

The discriminator from epiglottitis: croup has a BARKING cough and the child can usually swallow; epiglottitis has drooling, a toxic child and no barking cough — and you must NOT examine the throat.

Monitor & prognosis

Stridor at rest, work of breathing, response to steroid.

Usually self-limiting; steroids shorten/lessen it.

Source: NICE CKS Croup (2025)