What should you know about the sound of croup in infants?

Croup causes swelling around the larynx and upper windpipe. Because an infant's airway is small, that swelling can make airflow sound rough or high-pitched. Stridor describes noise during breathing in; it is more concerning when it continues while the infant is settled and resting. A barking cough and hoarse cry may appear with a runny nose or fever after a cold-like illness.

The sound alone cannot show how severe the illness is. Notice the infant's breathing effort, colour, alertness, and ability to feed. A recording made when the infant is calm may help a clinician understand the symptom, but do not delay care to make one.

Keep the infant upright against you and use a quiet voice. Limit handling and crying because distress can increase the work of breathing. If feeding is comfortable, offer the usual milk in smaller, more frequent amounts and monitor wet nappies. Avoid steam, smoke, and unprescribed cough medicines. Contact a child health clinician for advice, particularly when the infant is very young or the sound is new. If assessment shows significant upper-airway swelling, a clinician may discuss nebuliser treatment or another treatment plan.

Call emergency services or go to emergency care if the infant has noisy breathing while calm, ribs or neck pulling in with each breath, pauses in breathing, difficulty feeding because of breathlessness, drooling with trouble swallowing, unusual limpness, or blue, grey, or very pale lips and skin. Seek prompt medical advice if the cough or breathing noise is getting worse, feeds are reduced, or the infant has fewer wet nappies. Keep the infant upright while arranging help and do not place anything in the mouth to inspect the throat.

Ask whether the sound is stridor, what it means if it returns during sleep, how to support feeding, and which changes require emergency care. Tell the clinician whether the noise occurs only when the infant cries or also when calm, and describe the cough, temperature, feeding, and wet nappies.