What to Know About Laryngotracheobronchitis (Croup)

Laryngotracheobronchitis is a form of croup, the term for a common group of respiratory conditions that mostly affect infants and children. It’s highly treatable with corticosteroids, rest, and hydration.

Croup refers to a group of respiratory conditions that primarily affect children between ages 6 months and 3 years. Laryngotracheobronchitis is one form of croup that causes inflammation of the larynx (voice box), trachea (windpipe), and bronchi (airways in the lungs).

Other types of croup include laryngotracheitis and laryngotracheobronchopneumonitis, which differ only in the location and extent of the inflammation of the respiratory system. If your child receives a diagnosis of croup, your doctor will tell you which form it is.

Read on to learn more about what laryngotracheobronchitis is, what symptoms to look out for, and how to treat it.

What is it?

Croup refers to a group of respiratory conditions that affect about 3% of all children each year. The laryngotracheobronchitis form of croup is an infection that affects the trachea, larynx, and bronchi.

Young children and infants are much more likely to get it. But in very rare cases, teenagers or older adults may develop some milder symptoms.

Croup is a viral infection. In most cases, it’s spread through coughing and sneezing. Rarely, it can be a bacterial infection.

Like many respiratory conditions, croup is more common in late autumn to early spring. Though laryngotracheobronchitis is slightly more severe than laryngotracheitis, it’s still typically a mild condition.

Types of croup

Three core variants of croup exist, including:

• Laryngotracheitis: This involves inflammation of the larynx (voice box) and trachea (windpipe).
• Laryngotracheobronchitis: This extends further into the respiratory tract and involves the larynx, trachea, and bronchi. It can lead to slightly more severe symptoms than laryngotracheitis alone.
• Laryngotracheobronchopneumonitis: This involves inflammation that extends further into the lungs, including the alveoli (air sacs) as well. It may lead to the most severe symptoms of the three.

Symptoms

Common symptoms of croup include :

• a distinctive seal-like “barking” cough
• stridor , a high-pitched wheezing or whistling sound when inhaling
• hoarse voice
• difficulty breathing

Potential additional signs and symptoms include:

• fever
• nasal congestion
• increased breathing or heart rate
• restlessness
• irritation
• rash
• swollen lymph nodes
• red eyes

More serious symptoms to look out for include:

• cyanosis, a bluish tint to the skin, lips, or nails
• excess drowsiness or disorientation
• labored breathing signs like nasal flaring

Symptoms typically get worse at night. While the condition lasts for a few days to a week, symptoms are typically at their worst around days 3 and 4.

According to a 2023 review , more than 85% of children with croup have a mild form of the disease. Severe croup makes up less than 1% of all cases.

Causes

Croup, including laryngotracheobronchitis, is typically caused by viral infections. Some of the most common causes are parainfluenza viruses types 1 and 2.

Other potential viral causes include:

• respiratory syncytial virus (RSV)
• influenza A and B
• measles virus (in unvaccinated children)
• adenovirus

Less commonly, croup can be caused by bacterial infections, allergic reactions, or inhalation of irritants.

Diagnosis

Croup is typically diagnosed based on a physical exam. Your child’s pediatrician may listen to the cough and assess breathing. For instance, if the cough is characterized by a whooping sound instead of a barking or seal-like sound, it might be whooping cough .

Doctors can use a scoring system to determine the severity of the condition. In the case of an unclear diagnosis, the doctor may recommend a throat assessment chest X-ray to rule out more serious conditions like foreign body aspiration or epiglottitis .

Treatment

In general, treatment for croup depends on the severity of the condition.

Mild cases are typically treated with a single dose of the corticosteroid dexamethasone to reduce inflammation. Your pediatrician will also recommend plenty of rest and hydration.

Moderate to severe cases may require:

• nebulized epinephrine to reduce inflamed airways more rapidly
• corticosteroids like dexamethasone, budesonide, or prednisone
• in the case of low oxygen levels, oxygen therapy
• very rarely, in severe cases, intubation
• very rarely, antibiotics in the case of a primary or secondary bacterial infection

The outlook for the vast majority of children with croup is positive, and the condition can typically be managed safely with home care. Fewer than 2% of children need to be hospitalized.

When to contact a doctor

While most cases of croup can be managed safely at home, seek immediate medical attention if you notice your child has:

• extreme difficulty breathing or rapid breathing
• increased effort to breathe, including chest or neck muscles contracting
• bluish or pale skin color
• drooling or issues swallowing
• high fever that persists even with medication
• excessive drowsiness or agitation

Also contact a doctor if you notice any symptoms in a child younger than 6 months.

Learn more about when to worry about croup .

The bottom line

Croup is a common childhood respiratory condition that is typically mild and easily treatable with rest, hydration, and corticosteroids. Laryngotracheobronchitis is a specific variant of the condition that affects the larynx, trachea, and bronchi.

It’s important to call 911 or your local emergency number if your child experiences extreme issues with breathing, a bluish skin tone, or a high fever.