Croup vs RSV: Differences and Similarities

Medically Reviewed By Mia Armstrong, MD
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Croup and RSV (respiratory syncytial virus) are common illnesses in young children. RSV can cause the distinctive cough of croup, but it can also lead to other symptoms that need different treatments than croup. Croup and RSV respond well to at-home treatment. Always contact your child’s pediatrician for any concerning symptoms, especially if symptoms worsen. 

Here’s what to know about croup and RSV and how they vary from whooping cough. Understanding the differences can help you get your child the treatment they need.

What is croup?

Mother caring for young son who is resting in bed
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Croup is a condition caused by an infection, usually from parainfluenza viruses (HPIVs). This virus causes the upper airways to swell, including the vocal cords and windpipe.

Anyone can get the infection that causes croup. Although croup is usually not seen in older children and adults because their airways are larger. Croup can sometimes become serious in children ages 6 months to 3 years.

Croup is usually due to HPIV1 or HPIV2, but RSV can also cause it. Babies catch croup when they inhale droplets containing the virus that others cough or sneeze into the air.

Viral particles can also survive for a period on surfaces. A child may contract an infection that causes croup by touching unclean objects and then touching their face or their mouth.

Spasmodic croup is another form of croup due to allergy or stomach reflux. It causes breathing difficulties and cough. It comes on suddenly when stomach contents are pushed into the esophagus.

What is RSV?

RSV, or respiratory syncytial virus, is caused by a common type of virus known as orthopneumovirus. RSV affects people of all ages. Generally, it has mild symptoms that can be managed at home with rest and plenty of fluids. Nearly all children have developed RSV by age 2.

In infants, however, RSV can become serious. It’s the leading cause of pneumonia and bronchiolitis in children under a year old.

RSV spreads the same way many other viruses do. That is, through droplets left in the air when people sneeze or cough, or by touching unclean objects.

What are croup vs. RSV symptoms?

There are some distinctive symptoms of croup, RSV, and whooping cough, another childhood illness that can cause coughing and breathing difficulties.

Listening to your child’s breathing and cough is a good way to identify which infection your child might have. This information will also help you effectively communicate symptoms to your child’s pediatrician and get the appropriate treatment.

Croup symptoms

Croup symptoms start mild, like a cold, but can worsen and include:

  • loud upper respiratory cough, often compared to a barking sound or like a seal
  • hoarseness
  • squeaking noise when inhaling, known as stridor
  • low grade fever, less than 100.4°F (38°C)
  • runny nose and congestion
  • rapid breathing
  • retractions, when the skin pulls inward between ribs when breathing
  • pauses in breathing, known as apnea
  • skin or lips are turning blue or purple, known as cyanosis

Croup is more common in the cooler months. Symptoms may worsen as the day progresses and be worst at night, or they may seem to come and go.

Most children get better within a week, but a baby or young child may need hospitalization in severe cases.

Call your pediatrician or seek emergent medical care (call 911), if you notice that your child:

  • has retractions, when skin pulls inward between ribs when breathing
  • is pausing when breathing (apnea)
  • has blue or purple skin or lips (cyanosis)
  • has a squeaking noise when they inhale
  • if your child seems very distressed

RSV symptoms

RSV can lead to croup, but it can also develop differently and may go on to cause pneumonia and bronchiolitis, an infection of the small airways in the lungs. Symptoms include:

  • wet-sounding, lower respiratory cough
  • wheezing
  • fever
  • runny nose
  • lack of appetite
  • irritability, especially in infants
  • inactivity, especially in infants
  • difficulty breathing
  • retractions, skin contracting between ribs when breathing
  • apnea: pauses in breathing

RSV is most common from winter to early spring. Children with RSV need treatment. If it progresses, they may be hospitalized.

Call your pediatrician or seek emergency medical care (call 911), if your child is:

  • wheezing
  • pauses while breathing
  • has a deep cough
  • their skin contracts between their ribs as they breathe

Whooping cough symptoms

Whooping cough, or pertussis, is another common children’s infection associated with coughing. It is a bacterial infection rather than a viral infection. The illness progresses through three stages, from a mild cold-like illness to severe coughing to recovery with an increased risk for complications.

Whooping cough symptoms include:

  • hacking cough that comes in spells
  • gasping for breath
  • making a high-pitched whooping sound
  • vomiting from severe coughing
  • low grade fever
  • runny nose and congestion
  • lack of appetite
  • low heart rate
  • apnea

Babies under a year old can be at risk for serious illness from whooping cough, and babies under 6 months are often hospitalized. The pertussis vaccine helps prevents whooping cough. This vaccine series begins during infancy. Adults should also be vaccinated. Discuss this vaccine with your doctor or your child’s pediatrician.

What are the treatments for croup vs. RSV?

Treatments for these common childhood illnesses vary according to which virus is causing them.

Croup treatment

Croup often responds well to at-home treatments, including:

  • giving a fever reducer, such as acetaminophen, for children younger than 6 months
  • giving fever reducers, such as acetaminophen or ibuprofen, for children 6 months and older (ibuprofen should not be given to infants younger can 6 months)
  • soothing the child to prevent crying, which can worsen the cough
  • keeping the environment humid with a vaporizer or cool-mist humidifier
  • bringing your child outside to get fresh air
  • giving clear fluids to prevent dehydration

If your child seems very ill or symptoms worsen, contact your pediatrician. Your pediatrician may prescribe a steroid medication or assess whether further treatment is needed.

RSV treatment

RSV often responds well to at-home treatments, including:

  • giving a fever reducer, such as acetaminophen, for children younger than 6 months
  • giving fever reducers, such as acetaminophen or ibuprofen, for children 6 months and older (ibuprofen should not be given to infants younger can 6 months)
  • giving clear fluids to prevent dehydration
  • keeping the environment humid with a vaporizer or cool-mist humidifier
  • using nasal saline spread or gentle nasal suction

Most children with RSV get better in a few days.

If your baby is having trouble breathing or seems dehydrated, call your pediatrician right away. Some babies may need breathing assistance at a hospital with supplemental oxygen. Sometimes infants need intubation when a machine helps the infant breathe.


Croup and RSV are respiratory illnesses that are very common in babies and young children. Croup and RSV can affect people of all ages. Croup and RSV can lead to excessive coughing, including a barking cough with croup and a low wet cough with RSV.

Most children get better within a week, but if your baby or child seems to have difficulty breathing, call your pediatrician, call 911, or go to an emergency room immediately. Some babies need hospitalization for serious cases of croup or RSV.

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Medical Reviewer: Mia Armstrong, MD
Last Review Date: 2022 Oct 28
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