Doctors explain respiratory tract infection that often affects young children

Croup, a common upper respiratory tract infection in young children under age 6, can become severe and require hospitalization, doctors say in a new patient resource published in JAMA.

Best known for the distinctive hoarse cough it produces, croup is caused by a virus and is typically contagious during the first few days of the infection. Its spread can be prevented through good hand hygiene and good cough hygiene, the authors write.

“Often trigged by a virus such as the common cold, croup in younger children creates a cough that is described as a seal-like bark, which can be scary for families to hear,” said Dr. Elliot Melendez of the Johns Hopkins All Children’s Hospital in St. Petersburg, Florida, who co-wrote the patient resource.

Croup causes swelling of the larynx, or voice box, and the trachea, and its clinical name is laryngotracheitis. The inflammation can affect’s a child’s voice and ability to breathe.

“If not treated, it can lead to severe respiratory distress,” Melendez told Reuters Health in a phone interview. “This progression can have a psychological impact on families.”

The new patient page explains the symptoms, diagnosis and treatment options for croup.

Melendez and co-author Ioana Baiu of Stanford Hospital in California explain that croup typically occurs in the fall and winter months and is caused by the flu or parainfluenza viruses, adenovirus or other respiratory viruses. Like many respiratory infections, croup starts with a runny nose, fever and sore throat. Within a day or two, larynx swelling increases and leads to a characteristic “croupy” cough.

The cough is not dangerous, the authors emphasize. However, more severe forms of the infection can make it hard to breathe, causing a strained sound called stridor as air passes through the child’s narrowed airway. This is typically accompanied by rapid, shallow and labored breathing, and the child’s nostrils flare up and the ribs can be seen with each inhalation.

“Croup has seasonal variations like any other virus, and since the early symptoms may look like the common cold, it’s important for parents to be aware of developments and changes to ensure the correct diagnosis,” Melendez said.

Diagnosis is made based on symptoms and the characteristic cough. Testing for specific viruses with a swab can help but isn’t often necessary. In addition, an X-ray scan of the neck may distinguish croup from other causes but is rarely needed.

Similar to other viral upper respiratory infections, the recommended treatment for croup is supportive care. Mild infections can be managed at home with over-the-counter pain relievers, and cool mist may make breathing more comfortable. It’s also important to make sure the child stays hydrated.

“Croup is usually self-limited, but it’s also important to know when to seek care once a child shows signs of respiratory distress,” said Dr. Angela Mattke, a pediatrician at the Mayo Clinic’s Children’s Center and host of the “Ask The Mayo Mom” videos on Youtube.

Signs of respiratory distress include inspiratory stridor, labored breathing, bluish lips or decreased alertness. Pediatricians or emergency department doctors may use nebulized epinephrine to decrease inflammation and open the airway to allow better breathing, and steroids may be given as well.

Most children improve after one dose of epinephrine or steroids, although about 10 percent of kids may require further hospitalization for repeat doses and hydration.

In the rarest cases, a child may need a breathing tube until the infection subsides, and the infection may affect deeper structures of the lower airways or the lungs. A bacterial infection may also occur on top of the virus, which can require hospitalization and antibiotics, although these more severe infections typically affect immunocompromised children or those with underlying diseases such as asthma.

Melendez and Baiu provide links on the JAMA patient page to more information about croup from the Mayo Clinic and the U.S. Centers for Disease Control and Prevention.

After the virus that caused croup clears, the cough may linger for a few weeks.

“It’s important to teach kids how to wash their hands and how to cough into their arm rather than hands,” Mattke told Reuters Health by phone. “We typically see this in children in daycare and preschool, and it’s important to keep your kids healthy with proper hygiene, nutrition and sleep.”