Croup in babies

Croup is a contagious infection of the upper airways that can cause your baby or young child to cough with a barking sound. Read on to find out more about croup in babies, toddlers and older kids, including how to recognise the symptoms, how long croup lasts and what treatment could be needed.

What Is Croup?

Croup is a viral infection of the larynx (voice box) and the trachea (windpipe), which form the breathing tube connecting the mouth to the top of the lungs. With croup, in babies and toddlers or young children, inflammation of these passageways can cause them to narrow, making breathing more difficult.

One of the most obvious symptoms of croup is the way it sounds: Children with croup have a distinctive barking cough, often accompanied by a whistling or rasping noise (known as stridor) when breathing in.

Croup is common in babies, toddlers and young children especially between the ages of 6 months and 3 years.

Although a bout of croup can be scary – both for your child and for you as a parent – the good news is that in most cases it’s mild and can be treated at home.

However, it’s still important to seek medical advice urgently if your little one does seem to be experiencing a more severe attack.

What Causes Croup?

There are several viruses that can cause croup. The most common of these is known as the parainfluenza virus, but some of the other potential triggers include the influenza virus, rhinovirus (a common cause of colds and sniffles) and respiratory syncytial virus (RSV). Viruses that can cause croup in babies and toddlers may only lead to normal cold symptoms in adults or older children. However, younger kids and babies tend to have a narrower windpipe, so any swelling caused by the inflammation can have a more severe effect on breathing – this is what causes the symptoms of croup. Thankfully, this also means that usually your child will literally ‘grow out’ of being so susceptible to croup by around 5 or 6 years old, when his or her windpipe is more fully developed.

Is Croup Contagious?

Yes, croup is contagious. Just like other respiratory viruses, it can spread through coughs and sneezes in the air or by touching surfaces and objects that have been contaminated. Your child can get croup at any time of the year, but like several other common childhood illnesses it’s especially common during the autumn or early winter months. This might be because more viruses tend to be circulating around this time of the year. Keep in mind that having croup doesn’t result in immunity, so it is possible for your child to have croup more than once.

What Are the Symptoms of Croup?

The early croup symptoms sometimes seem like a common cold. So, for example, at first your child might just have a runny nose, sore throat, a cough and/or a high temperature. Eventually the characteristic croup symptoms can develop and are often worse in the evening or at night:

  • Fever (a high temperature of 38 degrees Celsius or more)

  • A distinctive, barking cough (which may sound like the noise a sealion makes)

  • A rasping or whistling sound when breathing in (especially when coughing or upset)

  • A hoarse-sounding voice

  • Difficulty breathing.

How Long Does Croup Last?

Croup usually clears up by itself within around 48 hours, although in rare cases it may linger for up to 2 weeks. See your child’s doctor if the symptoms of croup persist beyond a couple of days or if they seem to be getting worse.

How Can You Treat Croup at Home?

There is no specific treatment for the virus that causes croup. Keep in mind, it can’t be treated with antibiotics, which are used to treat bacterial infections but are not effective against viruses. If your baby or toddler has mild croup, it can help to

  • sit your child in an upright position

  • if necessary, treat the fever with a medicine recommended or prescribed by your doctor

  • make sure your child gets plenty of fluids to drink

  • focus on keeping your little one comfortable and calm – speak in a soothing voice and give plenty of hugs and kisses will help your little one feel better

  • try distracting your baby by reading a story, singing or blowing bubbles

  • don’t give your child over-the-counter cough or cold medicines

  • don’t put your child in a steamy room or get him or her to inhale steam

  • keep a close eye on your infant and seek medical attention if the symptoms seem to be getting worse.

When Should You Seek Medical Attention for Croup?

Call 111 or check in with your child’s doctor if you suspect your child has croup, even if it seems mild. If the symptoms worsen or don’t improve after 48 hours – or if you’re just worried – it’s definitely time to see the doctor.

Call 999 or go straight to your local A&E unit if you notice any of the following severe croup symptoms:

  • Blue lips or tongue

  • Struggling to breathe (signs of this can include flaring nostrils and/or the skin around your child’s tummy, ribs, breastbone or neck being sucked in with every breath)

  • Rapid breathing

  • Whistling or rasping sound when breathing while asleep or resting – not just when coughing or upset

  • Inability to drink or feed

  • Dribbling or inability to swallow

  • Seeming distressed or agitated

  • Sudden high fever (in a baby under 3 months old seek emergency medical attention if your child’s temperate is 38 degrees Celsius, or if you baby is aged 3 to 6 months and has a temperature that’s higher than 39 degrees Celsius)

  • Being unusually sleepy, floppy or difficult to wake.

What’s the Treatment for Moderate or Severe Croup?

If croup is diagnosed after a medical examination, the doctor may prescribe your child one of the following forms of treatment:

  • Oral steroid. Usually in liquid form for your child to drink, it helps reduce the airway swelling.

  • Nebuliser. This medicine – containing steroids and/or adrenaline – is inhaled as a mist using a special mask. Your child may need to stay a few hours for observation after the first dose, to make sure it’s working.

  • Hospitalisation. In very serious cases, your child may have to stay in hospital for treatment and so that doctors can monitor his or her condition closely.

The Bottom Line

Croup is an uncomfortable illness for your child, and it can be alarming for you as a parent too. Try to stay calm. If the symptoms become severe your doctor or local A&E unit can provide effective treatment, but usually it’s enough for you to help make your baby comfortable at home while you wait for the infection to pass. In typical cases, your baby will bounce back to his or her old self in a few days and both you and your little one will be able to breathe easy again.

How we wrote this article
The information in this article is based on the expert advice found in trusted medical and government sources, such as the National Health Service (NHS). You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.