Why are steroids contraindicated in patients with post-influenza (flu) bronchitis, especially those without a history of chronic respiratory diseases such as asthma or Chronic Obstructive Pulmonary Disease (COPD)?

Why Steroids Are Contraindicated in Post-Influenza Bronchitis

Steroids should not be used in post-influenza bronchitis because they provide no clinical benefit in acute bronchitis and may increase mortality when influenza is the underlying cause, particularly in critically ill patients. 1, 2

Evidence Against Steroid Use in Acute Bronchitis

The fundamental issue is that acute bronchitis in otherwise healthy adults does not benefit from corticosteroids regardless of the triggering pathogen. 1 The French guidelines explicitly state that systemic corticosteroids are not justified in the treatment of acute bronchitis in healthy adults, as the clinical course is generally spontaneously favorable after about 10 days. 1

Key Distinction: Acute Bronchitis vs. Chronic Bronchitis Exacerbations

This is a critical pitfall to avoid: steroids are beneficial for acute exacerbations of chronic bronchitis (COPD exacerbations) but harmful or useless in acute bronchitis in patients without underlying chronic lung disease. 1, 3

• For acute exacerbations of chronic bronchitis/COPD, a short course (10-15 days) of systemic corticosteroids is recommended and improves outcomes. 1, 3
• For acute bronchitis in healthy adults, steroids show no benefit in reducing symptoms, shortening illness duration, or preventing complications. 1

Specific Harm with Influenza

When influenza is the underlying cause, corticosteroids may actually increase mortality, particularly in severe cases. 2 A propensity score-matched study of 1,846 critically ill patients with confirmed influenza pneumonia found that corticosteroid administration was associated with increased ICU mortality (HR = 1.32,95% CI 1.08-1.60, p < 0.006). 2

Mechanism of Harm

• Corticosteroids suppress the immune response needed to clear viral infections. 2
• They may prolong viral shedding in bronchiolitis and likely have similar effects with influenza. 4
• The immunosuppressive effects outweigh any potential anti-inflammatory benefits in viral respiratory infections. 2

Common Clinical Pitfalls to Avoid

Do not prescribe steroids based on:

• The presence of wheezing (unless the patient has underlying asthma). 1
• Purulent sputum appearance, which is not associated with bacterial superinfection in acute bronchitis and does not justify steroid treatment. 1
• Hopes of shortening illness duration, as evidence shows no benefit for this purpose. 1

The most common error is mistaking acute bronchitis for asthma exacerbation or COPD exacerbation, both of which do benefit from steroid therapy. 1 Carefully assess for:

• History of chronic lung disease (asthma, COPD)
• Baseline lung function impairment
• Pattern of recurrent exacerbations

Treatment Algorithm for Post-Influenza Bronchitis

For otherwise healthy adults with post-influenza bronchitis:

• Provide symptomatic relief with central cough suppressants (codeine or dextromethorphan) for troublesome cough. 1
• Avoid antibiotics, as they are not indicated. 1
• Avoid NSAIDs at anti-inflammatory doses. 1
• Avoid corticosteroids entirely. 1

For patients with underlying COPD/chronic bronchitis experiencing an exacerbation triggered by influenza:

• Despite the influenza trigger, systemic corticosteroids remain indicated for the COPD exacerbation itself. 5
• A Swiss nationwide study found no evidence of worse outcomes when steroids were used for COPD exacerbations during influenza season. 5
• Use prednisone 40 mg daily for 5-7 days (or equivalent methylprednisolone 0.5 mg/kg/day). 1, 3

Special Populations

In children with viral bronchiolitis (including post-influenza), corticosteroids should not be used routinely, as systematic reviews of nearly 1,200 children showed no significant benefit in length of stay, clinical scores, or respiratory parameters. 4, 1