How do I treat croup?

What the evidence says

Croup usually starts like a cold and then causes a barky cough, hoarse voice, and sometimes a harsh, squeaky sound when breathing in (stridor). The Canadian Paediatric Society notes that in most cases croup sounds worse than it looks and clears up on its own within about 5 to 7 days. For mild croup, home care is usually enough: keep your child calm and comfortable, offer plenty of fluids, and use acetaminophen or ibuprofen for fever or discomfort (ibuprofen only if your child is drinking well, and not for babies under 6 months without checking with a doctor first).

Some Canadian sources suggest that taking your child into cool night air for a few minutes may ease symptoms, though evidence for humidifiers or mist therapy is weak, and cool mist humidifiers carry a risk of mold or bacterial contamination if not cleaned daily. Antibiotics, antihistamines, decongestants and over-the-counter cough/cold medicines are not helpful for croup and are not recommended for young children. If the barky cough or breathing is worse, doctors often give a single dose of the steroid dexamethasone by mouth.

Canadian and international randomized trials, summarized in a large Cochrane review, show this reduces symptoms within hours, shortens ER visits and hospital stays, and lowers the chance your child will need to return for care. For children with more severe breathing difficulty, an emergency department may also give nebulized epinephrine, which works quickly but wears off after a few hours, so those children are usually watched in hospital afterward. See a doctor or go to an emergency department if your child has rapid or difficult breathing, bluish lips, is drooling, can't lie down comfortably, seems very drowsy, or the fever lasts more than 72 hours (or your baby is under 6 months old with any fever).

Breathing trouble in croup can come on suddenly, so many parents choose to sleep in the same room as their child while symptoms last.