Little Kids

What parents need to know about croup in kids

Experts answer all your questions about croup in kids: What causes croup, common symptoms, and how to diagnose and treat this common childhood respiratory problem.

What parents need to know about croup in kids

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As a daycare teacher and mother of a preschooler, I was used to a familiar hacking chorus, so I wasn’t concerned when my three-year-old came home from daycare with a cough. I assumed he had a cold and some post-nasal drip (when excess mucus in the nose drips into the throat)—annoying, but not serious—and at worst he would have trouble falling asleep. I was wrong.

Later that night, my husband and I started to hear the telltale seal bark that suggests croup coming over the baby monitor. We went in to check on him and found his breathing was laboured and his cough was near-constant. When he began to drool, a sign of difficulty swallowing and airway constriction in croup in kids, we decided to take him to the hospital.

It was the right call. The ER doctor confirmed it was croup and gave him an oral dose of steroids to open his airways and help him breathe more easily. She told us he was likely to improve within the next twenty-four hours. He was back to himself by morning. We have since, tongue-in-cheek, referred to that steroid dose as the “miracle medicine”. Thankfully, though croup in kids is common, it rarely requires a trip to the ER.

What is croup?

Croup is a common childhood respiratory problem that causes swelling and narrowing in the voice box, windpipe, and breathing tubes that lead to the lungs. “Normally we have smooth, gentle airflow in the upper airway when we breathe,” says Jordan Glicksman, an otolaryngologist (ear, nose and throat surgeon) in Boston. “When there is a narrowing it causes turbulence (rough airflow) which leads to a high-pitched breathing sound, called a stridor.”

How do I know if my child has croup?

“The symptoms of croup typically start with a runny nose, congestion and then progress to include fever, hoarse voice, barky cough, and stridor when the child takes a breath in,” says Stephanie Liu, assistant clinical professor in the department of family medicine at the University of Alberta.

The calling card of croup is the barky cough. It has been likened to a seal bark because of its distinctive sound. The barking cough is made worse by crying, coughing, anxiety and agitation.

Croup is most common in the fall and early winter and symptoms are usually worse at night. Croup typically lasts under a week.


“Young children—particularly less than 6 years old—are most at risk for croup,” says Glicksman. “This is because younger children have smaller breathing passages and so it takes less inflammation to lead to a narrowing in the airway that causes noticeable stridor.” It is more common in boys than girls. 

What causes croup in kids?

Croup can be caused by a variety of viruses, but is usually caused by the same viruses that cause the common cold, particularly the parainfluenza virus. Croup occurs when any virus infects the larynx (voice box) and trachea (windpipe). The viruses that cause croup are contagious. Rarely, croup is caused by a bacterial infection.

Much less commonly, croup can also occur as the result of an allergy or reflux from the stomach. This is called spasmotic croup, and is similar to asthma. It has the same symptoms as viral croup, but it comes on suddenly, often in the middle of the night, and no fever is present. It is not contagious.

How is croup treated for children?

The treatment for croup depends on the severity of the symptoms.

Mild croup—in which children have a barky cough but no difficulty breathing and no stridor at rest—can be managed at home. Liu suggests parents or caregivers sit with the child in a bathroom filled with steam generated by a hot shower to improve symptoms. Exposure to cold night air may also lessen symptoms. Weather permitting, bundling up the child and taking them outside for up to twenty minutes, or standing in front of cool air from a window, may help calm symptoms. Keep the child upright and calm, and offer lots of clear fluids. If a fever is present, acetaminophen (Tylenol) or Ibuprophen (Motrin/Advil) can be administered, but don’t give the child cough or cold medicine.


“Moderate to severe croup, where a child is experiencing breathing problems and/or stridor at rest, should be evaluated by a doctor,” says Liu. If the child is having serious difficulty breathing, they should go immediately to the ER. If the breathing problems are less severe, and the doctor can see the child quickly, they can be checked by their family doctor or paediatrician.

Medications such as glucocorticoid (a type of steroid) and epinephrine (adrenaline) in an inhaled form may be administered to reduce inflammation of airways if necessary. These medications are typically given in the hospital before the child is released home, but a family doctor or paediatrician may prescribe a dose of oral steroid to take at home.

“Since this is usually a viral rather than bacterial infection, antibiotics are avoided unless there is a complication like a secondary bacterial infection, which is rare,” says Glicksman.

For all cases of croup, keep the child hydrated and do not let anyone smoke around the child or in the child’s house, which can further irritate the child’s lungs.

Is croup in kids dangerous? 

Croup is usually not dangerous—but there are some cases that warrant a doctor’s appointment or a trip to the emergency room, especially in children with asthma or other lung conditions.


Call the doctor or get immediate medical care if the child experiences trouble breathing, including very fast or laboured breathing. Indications of trouble breathing can include being too out of breath to walk or talk and pulling in of the neck and chest muscles when breathing. Stridor that is getting worse or occurs at rest also warrants medical attention. Signs of this include noisy, high-pitched breathing sounds both when inhaling and exhaling, and high-pitched breathing sounds when not crying or agitated.

Drooling or trouble swallowing is a sign of airway constriction and an indication the child needs medical care. If the child is pale, grey, or bluish around the nose, mouth, or fingernails, they may not be getting enough oxygen. This is an emergency situation—take the child to the hospital or call 911.

Watch for signs of dehydration (a dry or sticky mouth, few or no tears when crying, sunken eyes, thirst, peeing less), and for behavioural changes such as being tired, sleepy, or hard to waken, or seeming anxious, agitated, fatigued, or listless. This indicates a need for medical attention.

If treatments such as steam or cool air have not improved symptoms within thirty minutes, the child should also be seen by a doctor.

Croup patients are usually treated at the hospital and sent home. It is rare that a child with croup needs to be admitted.


Because croup attacks often happen at night and can become serious, it’s a good idea to let the child sleep in the same room as the parent or guardian for the duration of the illness.

Croup attacks are typically acute and medical care, if needed, tends to be immediate—but recurring croup infections also warrant a trip to the doctor. “When patients develop recurrent croup it’s important to consider the possibility of an underlying problem,” says Glicksman. “Otolaryngologists are specialized in evaluating these predisposing conditions.” If croup is recurring, the child should see a family doctor or paediatrician, who may give a referral for an ENT surgeon.

Can croup be prevented?

Preventing croup comes down to the same health and hygiene practices that we should all be practicing anyway. Frequent hand-washing, coughing or sneezing into elbows or sleeves, staying away from people who are sick, and staying away from people if you are sick go a long way to preventing the spread of germs, including the viruses that cause croup.

There is no vaccine for parainfluenza, the most common cause of croup, but staying up to date on vaccinations—including the flu shot—helps to prevent some of the less common but more serious upper airway infections. Any of these viruses, including the flu, can cause croup or make croup harder to manage.

Croup is unpleasant to experience and scary to watch. After my son’s episode of croup, I was constantly listening for that bark, just in case. Thankfully, croup is usually not serious, can be treated, and typically goes away quickly.

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