Croup vs. whooping cough: What’s the difference?

Croup and whooping cough are two respiratory infections that cause similar symptoms, such as an unusual sounding cough, fever and a runny nose. These illnesses are highly contagious, and whooping cough could possibly lead to complications for some infants. Although they have many similarities, there are some key differences between croup and whooping cough that parents and other caregivers should be aware of.

One of the biggest differences between croup and whooping cough is the cause. Whooping cough, or pertussis, is a bacterial infection caused by Bordetella pertussis. When the bacteria enter the body, they attach to tiny hairs along the lining of the respiratory tract, causing the airways to swell.

Croup is usually caused by viruses like the respiratory syncytial virus (RSV), influenza, adenovirus and parainfluenza. The infection usually begins in the nose and throat and then moves deeper into the respiratory system, causing inflammation around the voice box and in the windpipe.

The diphtheria-tetanus-pertussis (DTaP) vaccine provides effective and safe protection against whooping cough. This vaccine is administered through five doses, starting at 2 months of age and ending between the ages of 4 and 6 years. Adults between the ages of 19 and 64 should typically receive a one-time booster of the vaccine. Older adults age 65 years and older may need an additional booster if they’re frequently in close contact with children under the age of  
1 year.

There is no vaccine available for croup, but you can take some steps to lower the risk of contracting or spreading the illness:

• Wash your hands frequently
  
• Encourage children to cover their mouths and noses when they cough or sneeze
• Wash toys and personal belongings frequently
• Throw away used tissues promptly
• Keep children home from school or day care when they’re sick or there’s a croup outbreak
• Get vaccinated on schedule as directed by your healthcare provider for viruses that may lead to croup, such as influenza, Haemophilus influenzae (Hib) and measles. Although there isn't a vaccine for croup, there are vaccines against viruses that can lead to croup.

Croup and whooping cough differ in terms of prevalence. Thanks to the DTaP vaccine, whooping cough is no longer common in the U.S. In 2021, there were only 1,600 reported cases of the illness nationwide.

Compared to whooping cough, croup is much more common. About 3% of all children in the U.S. get croup each year. 

How healthcare providers treat croup and whooping cough also differs. Because whooping cough is caused by bacteria, the infection can be treated with antibiotics. A cool mist humidifier may help to ease coughing while the medication gets to work.

Antibiotics aren’t effective for treating croup. For mild cases, healthcare providers typically recommend taking over-the-counter pain relievers to control fever and drinking warm, clear fluids to ease coughing.

Seek medical attention for children with shortness of breath and severe inflammation in the airways.

The amount of time it takes to fully recover from croup and whooping cough is another key difference between these illnesses. 

Mild cases of croup usually resolve in a couple of days, but symptoms may continue for a week.

Even after the initial whooping cough infection clears, children may continue to have a nagging cough for weeks or months due to bacteria-related damage that takes time to heal.

The severity and risks for serious health complications also separate croup and whooping cough. Severe croup can be life-threatening but accounts for only around 1% of cases. Fortunately, around 85% of croup cases are mild. 

Comparatively, the risk for severe complications from whooping cough is higher, especially in infants. Complications from severe whooping cough include difficulty breathing, pneumonia and convulsions. 

Around one-third of babies who develop whooping cough need to be hospitalized, and around 0.6% of those hospitalized for the condition contract a brain disease called encephalopathy. Whooping cough can also be fatal. Around 1% of babies hospitalized for whooping cough die from the illness.

Although there are distinctive differences between croup and whooping cough, it can be difficult to determine which condition your child has without seeing a medical professional. Your child’s healthcare provider can conduct an examination and order tests to determine what’s causing their symptoms. Then, they can prescribe treatments and give you advice on how best to care for your child while they recover.

Updated October 2023.