Influenza (& other Lower Respiratory Tract Viruses)

Diagnosis of exclusion, or by nasopharyngeal swab for antigen detection (some tests only detect Influenza A).

Clinical Presentation:
  • Abrupt onset fever & generalized myalgias.  Headache.
  • Cough, not very productive.
  • Worst on Days #1-2, begins to abate Day #3-4, resolved by Day #5.
  • No true dyspnea.  No signs of respiratory distress.
  • Normal Lung Exam
Diagnostic Approach
During Influenza season: Late November through April.
  • No CXR needed.  Obtain swab for antigen if available with same-day results.
Other times of year:
  • Get CXR if fever persists 3 days
Always obtain CXR to R/O pneumonia if:
  • Compromised Host
  • Focal rales
  • True Dyspnea.  Signs of respiratory distress.
  • Symptoms getting worse on Day #3, or not diminishing by Day #4.

See our postings  Acute Cough – 2 and Fever.