Why does croup cause fever?

Fever is a common presentation of Croup. A raised temperature can occur as the body responds to the infection, alongside a barking cough, hoarse voice, runny nose, or noisy breathing. The height of a temperature does not by itself show how serious the airway swelling is. A child's alertness, drinking, skin colour, and work of breathing give more useful information about urgency.

Fever can also occur with infections other than croup. A clinician may consider the whole pattern, including how long symptoms have been present and whether the child has signs outside the usual upper-airway symptoms.

Offer drinks often and allow rest. Dress your child comfortably rather than trying to make them cold. If they are uncomfortable, use a suitable fever or pain medicine according to the product instructions and their clinician's advice. Keep them calm, since crying can make the croup cough and breathing noise worse. Check breathing during the illness, including while they are resting.

Get urgent medical help if there is noisy breathing while resting, obvious difficulty breathing, pulling in around the ribs or neck, blue or grey lips, drooling with trouble swallowing, marked sleepiness, or a child who cannot stay awake. Seek same-day medical advice for a child who drinks very little, has fewer wet nappies or trips to the toilet, or seems to be getting worse.

Ask whether the child's breathing pattern needs treatment for airway swelling, how to give comfort medicine safely, and which symptoms should lead you to seek help overnight. Tell the clinician about chronic illnesses, regular medicines, and any difficulty taking fluids.