What is the best corticosteroid for treating chest inflammation related to influenza (flu)?

Corticosteroids Should NOT Be Used for Chest Inflammation Related to Influenza

Corticosteroids are contraindicated in influenza-related chest inflammation and pneumonia, as they are associated with significantly increased mortality, delayed viral clearance, and higher rates of secondary bacterial infections. 1, 2

Evidence Against Corticosteroid Use

The evidence consistently demonstrates harm from corticosteroid therapy in influenza:

• Meta-analyses of observational studies show a mortality odds ratio of 3.06 (95% CI 1.58-5.92) associated with corticosteroid use in influenza patients 1, 2
• Analysis of high-quality studies with low risk of bias confirms these findings (OR 2.82; 95% CI 1.61-4.92) with increased risk of superinfection 2
• A large multicenter study of influenza-associated ARDS found that early corticosteroid treatment (≥200 mg hydrocortisone equivalent within 3 days) was independently associated with increased hospital mortality (adjusted OR 5.02,95% CI 2.39-10.54) 3
• Higher doses and earlier initiation of corticosteroids are associated with worse mortality outcomes 3, 4

Formal Guideline Recommendations

Major professional societies explicitly recommend against corticosteroid use:

• The American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) recommend NOT using corticosteroids routinely in adults with severe influenza pneumonia (conditional recommendation, low-quality evidence) 1
• The Society of Critical Care Medicine (SCCM) and European Society of Intensive Care Medicine (ESICM) recommend avoiding corticosteroids in adults with influenza (conditional recommendation, very low-quality evidence) 1, 5

Mechanisms of Harm

Corticosteroids cause harm in influenza through multiple mechanisms:

• Suppression of innate immunity, which is fundamental for defense against influenza virus 1
• Increased risk of secondary bacterial infections (pooled OR 2.74,95% CI 1.51-4.95) 1, 4
• Delayed viral clearance from the respiratory tract 6, 2
• Longer duration of mechanical ventilation and ICU stay 7

Recommended Treatment Instead

The appropriate management of influenza-related chest inflammation includes:

• Antiviral therapy with oseltamivir should be initiated as soon as possible, ideally within 48 hours of symptom onset, though later initiation still provides benefit 1, 5
• All patients with influenza pneumonia must receive antibiotics to cover bacterial coinfection or secondary infection, including coverage for S. pneumoniae, H. influenzae, M. catarrhalis, and Staphylococcus aureus 6, 1, 5
• Preferred antibiotic regimens include doxycycline or co-amoxiclav 6
• Macrolides (clarithromycin or erythromycin) are alternatives for penicillin-allergic patients 6

Critical Exceptions and Caveats

There are specific situations where corticosteroid decisions differ:

• Patients with COPD exacerbation without confirmed influenza pneumonia should receive corticosteroids per standard COPD guidelines 6, 5
• Patients already on chronic corticosteroid therapy should continue their baseline dose to avoid adrenal insufficiency, but efforts should be made to reduce to the lowest effective dose 2
• Abrupt cessation of chronic corticosteroids (>5 mg/day prednisone equivalent) can cause acute adrenal insufficiency and should be avoided 2
• In the specific context of COVID-19 myocarditis with pneumonia requiring supplemental oxygen, corticosteroids may be beneficial, but this does not apply to influenza 6

Common Pitfall to Avoid

The most important pitfall is the temptation to use corticosteroids in severely ill influenza patients based on their benefit in other conditions like bacterial sepsis or community-acquired pneumonia without influenza. The evidence clearly shows that what works in bacterial pneumonia does not work in influenza pneumonia—in fact, it causes harm. 5, 4, 8