Constrictive bronchiolitis

Constrictive Bronchiolitis

Constrictive bronchiolitis, also known as obliterative bronchiolitis, is a rare and serious lung condition characterized by the obstruction of the smallest airways of the lungs, the bronchioles, due to inflammation and fibrosis. This condition leads to progressive respiratory symptoms and can significantly impact a patient's quality of life.

Pathophysiology

Constrictive bronchiolitis involves the inflammation and subsequent fibrosis of the bronchioles. The bronchioles are small air passages in the lungs that lead to the alveoli, where gas exchange occurs. In constrictive bronchiolitis, the walls of these airways become thickened and scarred, leading to narrowing and obstruction. This process is often irreversible and can result in significant airflow limitation.

The condition is often associated with exposure to toxic fumes, viral infections, or as a complication of lung transplantation or bone marrow transplantation. It can also be idiopathic, meaning the cause is unknown.

Clinical Presentation

Patients with constrictive bronchiolitis typically present with:

- Progressive dyspnea: Shortness of breath that worsens over time. - Cough: A persistent, non-productive cough. - Wheezing: Due to narrowed airways. - Fatigue: Resulting from decreased oxygenation.

The onset of symptoms can be insidious, and the condition may be misdiagnosed as asthma or chronic obstructive pulmonary disease (COPD) in its early stages.

Diagnosis

The diagnosis of constrictive bronchiolitis is challenging and often requires a combination of clinical, radiological, and histopathological findings. Key diagnostic tools include:

- Pulmonary function tests (PFTs): These often show an obstructive pattern with reduced forced expiratory volume (FEV1). - High-resolution computed tomography (HRCT): May reveal mosaic attenuation, air trapping, and bronchial wall thickening. - Lung biopsy: Considered the gold standard for diagnosis, showing bronchiolar fibrosis and obliteration.

Management

There is no definitive cure for constrictive bronchiolitis, and treatment focuses on managing symptoms and slowing disease progression. Management strategies include:

- Corticosteroids: To reduce inflammation, although their effectiveness is variable. - Immunosuppressive therapy: In cases related to transplantation. - Bronchodilators: To relieve symptoms of airway obstruction. - Oxygen therapy: For patients with significant hypoxemia.

Prognosis

The prognosis for patients with constrictive bronchiolitis varies depending on the underlying cause and response to treatment. The condition is often progressive, and in severe cases, it can lead to respiratory failure.

Also see

• Bronchiolitis obliterans syndrome
• Chronic obstructive pulmonary disease
• Interstitial lung disease
• Lung transplantation