Croup: Symptoms and Treatment Options

Medically Reviewed By Mia Armstrong, MD
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Croup is inflammation of the voice box and windpipe. Croup causes a “barking” cough, making breathing difficult. Swelling of the airway can result in a high-pitched sound — known as stridor — during inhalation. Croup is a common viral respiratory illness in children younger than 5 years old. Croup can become dangerous if the windpipe swells so much that breathing is restricted. A symptom of severe croup is stridor in a child when they are at rest — sitting or not actively moving around. The child may not be getting enough oxygen into their blood.

Contact a doctor for stridor, but get immediate medical help if the child has stridor and difficulty breathing.

This article explains the symptoms, cause, and treatment of croup. You will also learn about croup diagnosis, potential complications, and get answers to frequently asked questions.

What is croup?

Mom holding young child who is sick
Ray Kachatorian/Getty Images

Croup is inflammation of the voice box and windpipe, usually from a viral infection. The lining of the airway swells, which makes it narrower than usual. This can cause stridor — a high-pitched sound during inhalation. It is from air moving through the narrowed airway.

According to American Academy of Pediatrics (AAP), there are three kinds of croup:

  • Viral croup: This is the most common type of croup. A child with viral croup usually has a fever.
  • Spasmodic croup: This type of croup is from an allergy or acid reflux. It is like asthma. It may come on suddenly and does not typically cause a fever.
  • Croup with stridor: A child with a mild case of croup may have stridor when they are active. The child may have severe croup if stridor occurs when the child is resting.

Medical terms for croup include “laryngotracheitis” and “laryngotracheobronchitis.”

Due to differences in airway anatomy in children versus adults, croup in children can become a serious condition and restrict breathing. Continued swelling can make breathing an exhausting effort, and your child may feel too tired or unable to eat, drink, or cough.

Knowing the symptoms of croup can help with early diagnosis and treatment and reduce the chance of complications.

What are the symptoms of croup?

At times, any of these symptoms can be severe:

  • bark-like cough that worsens at night
  • high-pitched sounds with inhalation, known as stridor
  • difficulty breathing and sleeping
  • difficulty swallowing, which can cause drooling
  • hoarse voice
  • lack of energy
  • fever, which is usually low but may be a high 104°F (40°C)
  • restlessness
  • episodes of vomiting from coughing too hard

Croup symptoms may resemble a mild cold or upper respiratory infection for the first few days. As the cough worsens and the airway becomes more swollen, breathing becomes more labored and symptoms turn into the characteristic bark-like cough and stridor.

Learn about sounds your lungs make here.

Duration

Croup typically lasts 3–7 days with symptoms becoming more severe on day 3 or 4. Symptoms are usually manageable at home, explains the AAP. The first few nights of coughing can be uncomfortable.

When to contact a doctor

Contact a healthcare professional if you hear high-pitched sounds when your child breathes in. There are medications to reduce swelling, improve breathing, and reduce the chance of complications.

Severe croup can quickly become life threatening because your child may not be getting enough oxygen. Get immediate medical care — call 911 — for any of these symptoms:

  • stridor at rest or that gets louder with each breath
  • chest retractions that are visible between the ribs as the child inhales
  • difficulty breathing
  • pale or bluish colored skin or lips
  • anxiety or agitation with the effort to breathe
  • difficulty speaking due to lack of breath
  • rapid heart rate
  • difficulty swallowing, which may result in drooling

What causes croup?

Croup is usually a viral infection of the voice box and windpipe. It is most often caused by a parainfluenza virus. These viruses cause lower and upper respiratory infections and spread between people by airborne droplets.

Other viruses that can cause croup include SARS-CoV-2, the virus that causes COVID-19, adenovirus, influenza, measles, and respiratory syncytial virus.

Less common causes of croup include acid reflux, allergies, inhalation of an irritant, and bacterial infections.

Learn about upper respiratory infections here.

Risk factors

One reason why croup is more common in children between 3 months and 5 years old is that their airways are smaller compared with older children. This makes them more prone to experience symptoms from the inflammation of the voice box and windpipe area.

Other factors that increase the chance of croup include:

  • acid reflux
  • exposure to someone with croup
  • anatomic narrowing of the airways, such as polyps or scarring
  • inhalation of an irritant or allergen

How can you prevent croup?

Exposure to some germs can be hard to manage. However, you may be able to lower your child’s chance of getting croup by:

  • avoiding close contact with anyone who has a respiratory infection
  • washing your and your child’s hands frequently
  • ensuring that your child’s immunizations are up to date, especially diphtheria, Haemophilus influenzae type b, influenza, measles, and COVID-19 vaccines

Refer to the Centers for Disease Control and Prevention for recommended childhood vaccinations.

How do you diagnose croup?

A healthcare professional typically diagnoses croup by a physical exam and symptoms. They make take a throat swab to rule out a bacterial cause.

They will also evaluate the severity of croup to help determine the type of medical treatment necessary. They look for these signs:

  • stridor at rest
  • chest retractions, which appear as skin and muscle being sucked in between the ribs with each breath
  • cyanosis, which is when the skin, gums, fingernails, and mucous membranes are paler than usual or have a bluish hue due to a lack of oxygen in the blood
  • low air intake
  • low level of alertness

Learn what oxygen level means here.

How do you treat croup?

Croup usually goes away on its own within 1 week, perhaps with over-the-counter medications for comfort.

At-home treatment for mild cases

Care tips include:

  • acetaminophen (Tylenol) for fever and mild pain
  • ibuprofen (Advil, Motrin) for fever and mild pain, in children 6 months and older
  • not treating croup with cough medicines unless your child’s healthcare practitioner directs you
  • fluids

A common at-home treatment to calm breathing is to place the child in a steamy bathroom, place a humidifier or vaporizer in the child’s room, or bring the child outside if the air is cool. The AAP explains there are no studies showing this is effective for croup.

However, it is helpful to reassure your child. Croup tends to worsen at night and your child may wake up alarmed. Be prepared with some soothing words or a calming toy or book.

Severe croup

More severe croup may require care and supplemental oxygen in a hospital. Medication options may include steroid therapy, such as prednisolone (Pediapred) or dexamethasone (Baycadron), to reduce inflammation and swelling. Nebulized epinephrine may also ease breathing.

Learn about nebulizer breathing treatments here.

What are the potential complications of croup?

Croup can be serious, especially in infants, if airway swelling continues or suddenly worsens. Complications of croup include:

  • partial lung collapse
  • bacterial infection of the windpipe
  • dehydration
  • respiratory arrest or distress

Other frequently asked questions

Below are other questions that people ask about croup.

What is it called when adults get croup?

Adults can get the infections that cause croup, but they are less like to develop symptoms like stridor because the airway is larger and more rigid compared with a child’s airway. The medical term for croup is “laryngotracheitis.”

Is croup contagious to adults?

The viruses that cause croup are contagious to adults.

Does croup go away on its own?

Yes, croup goes away on its own in many cases. Medications and supplemental oxygen may be necessary for severe croup. They do not clear the infection, but they do reduce swelling and improve breathing.

Summary

Croup is a childhood respiratory illness commonly due to a viral infection. It affects the voice box and windpipe. Symptoms include a bark-like cough and possibly stridor, a high-pitched whistling sound as the person inhales.

Croup usually lasts less than 7 days. Steroids and other treatments may be necessary to ease breathing. Children with severe croup may need care in a hospital.

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Medical Reviewer: Mia Armstrong, MD
Last Review Date: 2022 Jun 29
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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