What are the causes and treatments of pulmonary inflammation (Pneumonitis)?

From the Guidelines

Inflammation in the lungs should be treated promptly with antibiotics for bacterial causes, antiviral medications for viral causes, and corticosteroids to reduce inflammation, as emphasized by recent guidelines 1. The treatment approach depends on the underlying cause of the inflammation, which can range from bacterial infections like Streptococcus pneumoniae, viral infections such as influenza or COVID-19, to fungal infections, chemical exposure, and smoking. For bacterial infections, antibiotics such as amoxicillin 500mg three times daily for 5-7 days or azithromycin 500mg on day one followed by 250mg daily for 4 days are commonly prescribed. Antiviral medications are used for viral causes, and corticosteroids like prednisone (20-60mg daily, tapered over 1-2 weeks) are used to reduce inflammation. Additionally, bronchodilators such as albuterol (2 puffs every 4-6 hours as needed) can help open airways, and supplemental oxygen may be necessary if blood oxygen levels are low. Supportive measures include rest, adequate hydration, and over-the-counter pain relievers like acetaminophen (650mg every 6 hours as needed) for fever and discomfort. In cases of immune checkpoint inhibitor-induced pneumonitis, management strategies include holding or discontinuing the immune checkpoint inhibitor (ICI), considering pulmonary and infectious disease consultations, and initiating corticosteroids like methylprednisolone 1 mg/kg/day, as outlined in consensus recommendations 1. For chronic inflammatory lung conditions, long-term medications such as inhaled corticosteroids (like fluticasone 110-220mcg twice daily) may be prescribed, and avoiding triggers like smoke, pollution, and allergens is crucial for prevention and management. Key considerations in managing lung inflammation include:

• Identifying the underlying cause to guide treatment
• Prompt initiation of appropriate therapy to prevent complications
• Monitoring for signs of worsening inflammation or treatment failure
• Adjusting treatment strategies based on patient response and severity of symptoms, as guided by recent clinical evidence 1.

From the Research

Causes of Inflammation in Lungs

• Inflammation in the lungs is usually caused by pathogens or by exposure to toxins, pollutants, irritants, and allergens 2
• The inflammatory response is complex and involves a variety of mechanisms to defend against pathogens and repair tissue 2
• Genetic and environmental factors, and infection are the major causes of dysregulation of various functions of the lung, leading to inflammatory diseases 3

Types of Inflammation in Lungs

• Acute inflammation is seen in pneumonia and acute respiratory distress syndrome (ARDS) 2
• Chronic inflammation is represented by asthma and chronic obstructive pulmonary disease (COPD) 2
• Inflammatory diseases such as asthma, chronic bronchitis, interstitial lung diseases, and acute lung injury leading to adult respiratory distress syndrome feature inflammation as part of their pathophysiology 4

Treatments for Inflammation in Lungs

• Azithromycin 1g once daily for 3 days is at least as effective as amoxicillin-clavulanate 875/125 mg twice daily for 7 days in the treatment of adult patients with community-acquired pneumonia 5
• A 5-day course of azithromycin (500 mg on day 1, plus 250 mg/day on days 2-5) is equally effective as a 10-day course of amoxicillin/clavulanic acid (625 mg every eight hours) in the treatment of lower respiratory tract infections 6
• Therapeutic interventions targeting the balance of Th1, Th2, Th9, and Th17 responses have been used in the treatment of inflammatory diseases such as asthma and COPD 3