Corticosteroids in Influenza A: Avoid Routine Use
Corticosteroids should NOT be routinely administered to patients with influenza A infection, including those with underlying asthma or COPD, as meta-analyses demonstrate increased mortality (OR 3.06,95% CI 1.58-5.92) in influenza patients receiving steroids. 1
Primary Evidence Against Steroid Use in Influenza
The most authoritative guidance comes from multiple professional societies that explicitly recommend against corticosteroid use in influenza pneumonia:
The ATS/IDSA 2019 guidelines state that meta-analyses of predominantly retrospective studies suggest mortality may be increased in patients who receive corticosteroids for influenza pneumonia, likely reflecting the critical importance of innate immunity in defense against influenza (as opposed to bacterial pneumonia where steroids may help). 2
The British Infection Society and British Thoracic Society recommend against corticosteroids in hospitalized influenza patients, focusing instead on antivirals, antibiotics for bacterial co-infection, and supportive care. 1
The SCCM/ESICM recommend avoiding corticosteroids in adults with influenza (conditional recommendation, very low-quality evidence). 1
Supporting Research Evidence
Two high-quality propensity-matched studies reinforce this recommendation:
A 2018 Spanish multicenter study of 1,846 critically ill patients with severe influenza pneumonia found that corticosteroid use was associated with increased ICU mortality (HR 1.32,95% CI 1.08-1.60, p<0.006) after propensity score matching. 3
A 2011 South Korean study of 245 critically ill patients with H1N1 found 90-day mortality of 58% in the steroid group versus 27% in the no-steroid group (adjusted OR 2.20,95% CI 1.03-4.71), with increased rates of superinfection. 4
Mechanism of Harm
Corticosteroids compromise the innate immune response that is fundamental for defense against influenza virus, potentially facilitating secondary bacterial infections. 1 This differs fundamentally from bacterial pneumonia, where modulating excessive inflammation may be beneficial. 2
Critical Exception: Continue Steroids for Underlying Disease
This recommendation does NOT override clinically appropriate steroid use for comorbid conditions. 2, 1
Patients requiring corticosteroids for their underlying disease should continue therapy:
Asthma exacerbations: Continue necessary steroid therapy for severe asthma exacerbations triggered by influenza. 1
COPD exacerbations: Continue steroids for COPD exacerbations, as the benefit for the underlying lung disease outweighs influenza-related risks. 1
Chronic steroid users: Patients on chronic systemic steroids should continue their regimen but attempt dose reduction to the lowest effective level to avoid adrenal insufficiency while minimizing immunosuppression. 1
Recommended Treatment Approach Instead
Antiviral Therapy (First Priority)
Oseltamivir 75 mg orally twice daily for 5 days is the primary treatment for all patients with influenza A pneumonia. 2, 1
Greatest benefit occurs when started within 48 hours of symptom onset, but hospitalized patients who are severely ill may benefit even beyond 48 hours. 2, 1
Dose reduction to 75 mg once daily is required if creatinine clearance is <30 mL/min. 1
Antibiotic Coverage (Second Priority)
All patients with influenza pneumonia require antibiotics to cover bacterial co-infection or secondary infection, particularly S. pneumoniae, H. influenzae, M. catarrhalis, and S. aureus. 1
For non-severe pneumonia: Oral co-amoxiclav or doxycycline. 1
For severe pneumonia: Intravenous broad-spectrum β-lactamase stable antibiotic plus a macrolide. 1
Special Consideration: Refractory Septic Shock
The only scenario where steroids may be considered in influenza is refractory septic shock unresponsive to adequate fluid resuscitation and vasopressor support, following Surviving Sepsis Campaign recommendations. 2 However, even in this context, the influenza-specific mortality risk must be carefully weighed.
Common Pitfall to Avoid
Do not reflexively prescribe steroids for "severe pneumonia" in influenza patients, even if you would do so for bacterial CAP. The pathophysiology differs fundamentally—influenza requires intact innate immunity, while bacterial pneumonia may benefit from anti-inflammatory effects. 2, 1