Pneumonitis

Diagnosis

To diagnose pneumonitis, your doctor reviews your medical and family history, discusses your symptoms, and asks about any medicines or previous treatments, such as cancer therapy. They may also inquire about repeated or ongoing exposure to dust, chemicals, birds, or mold through home, work, or hobbies.

During a physical exam, a healthcare professional listens to your lungs with a stethoscope.

In some cases, avoiding the suspected environmental trigger for several weeks may help confirm a diagnosis of hypersensitivity pneumonitis.

Tests that may help differentiate pneumonitis from other lung conditions include:

Blood tests
• Detect infections and check for antibodies indicating allergen exposure
• Arterial blood gas measures oxygen and carbon dioxide levels

Imaging tests
• Chest X-ray shows areas and severity of lung inflammation and may rule out conditions such as pneumonia
• CT scan provides detailed images of lung changes and helps evaluate lung damage

Pulmonary function tests
• Spirometry measures how much air the lungs can hold and airflow speed
• Lung volume tests measure air held at different points during breathing
• Lung diffusion tests assess oxygen and carbon dioxide exchange
• Pulse oximetry measures oxygen saturation; a six-minute walking test may be used to check oxygen levels during activity

Bronchoscopy
A thin tube is inserted through the nose or mouth into the lungs. Lung sections may be flushed with a saline solution (lavage) to collect cells, and small tissue samples may be taken for testing.

Surgical lung biopsy
In cases where bronchoscopy cannot reach affected areas, larger tissue samples may be collected through minimally invasive surgery to confirm the diagnosis.

Treatment

Treatment for pneumonitis depends on the underlying cause.

Hypersensitivity pneumonitis
• Avoid the triggering substance, which may involve changing jobs or hobbies
• Wear protective gear such as masks or respirators
• Improve ventilation in affected areas
• Reduce mold growth in hot tubs, humidifiers, carpets, and water-damaged materials

Corticosteroids can reduce lung inflammation, usually taken as pills for a limited period. Inhaled corticosteroids may also help. Bronchodilators relax airway muscles to ease breathing.

Drug-induced pneumonitis
• Mild cases may not require treatment
• Severe cases may need corticosteroids or other immune-modulating medications
• The causative medicine may be stopped or adjusted

Radiation-induced pneumonitis
• Mild symptoms may not need treatment
• Severe cases are usually treated with corticosteroids

Treatment for severe pneumonitis
• Oxygen therapy via mask or nasal cannula, sometimes needed continuously
• Pulmonary rehabilitation to improve daily functioning and manage symptoms
• Lung transplant for severe, irreversible lung damage