Respiratory bronchiolitis

Respiratory bronchiolitis is a common, mild inflammation of the bronchioles, the smallest air passages in the lungs. It is typically associated with cigarette smoking and is often discovered incidentally during lung biopsies or autopsies.

Etiology

The primary cause of respiratory bronchiolitis is long-term exposure to cigarette smoke. However, it can also occur due to other forms of inhaled irritants. The condition is most common in current or former smokers, particularly those between the ages of 20 and 40.

Pathophysiology

In respiratory bronchiolitis, the bronchioles become inflamed and filled with pigmented macrophages. These are immune cells that have engulfed particles of inhaled tobacco smoke. Over time, this can lead to the development of interstitial lung disease, a group of disorders characterized by progressive scarring of lung tissue.

Symptoms

Respiratory bronchiolitis is often asymptomatic, meaning it does not cause noticeable symptoms. When symptoms do occur, they may include shortness of breath, a dry cough, and wheezing. In severe cases, respiratory bronchiolitis can lead to respiratory failure.

Diagnosis

Diagnosis of respiratory bronchiolitis is typically made based on a combination of patient history, physical examination, and imaging studies. High-resolution computed tomography (HRCT) can be particularly useful in identifying the characteristic patterns of inflammation and damage associated with the condition.

Treatment

The primary treatment for respiratory bronchiolitis is to stop smoking. In some cases, corticosteroids may be used to reduce inflammation. However, the effectiveness of this treatment is uncertain.

Prognosis

The prognosis for individuals with respiratory bronchiolitis is generally good, particularly if they stop smoking. However, in some cases, the condition can progress to more serious forms of interstitial lung disease.

See also

• Bronchioles
• Interstitial lung disease
• Cigarette smoking