Synopsis
Recognise viral lower-respiratory disease, separate it from bacterial coinfection and non-infective mimics, deliver organism-specific antiviral or anti-inflammatory treatment when eligible, and apply current UK infection-control and escalation pathways.
- Influenza and SARS-CoV-2 can produce primary viral pneumonitis, trigger decompensation of chronic disease and permit secondary bacterial pneumonia; RSV and other viruses matter particularly in older or immunocompromised adults.
- Use the current local respiratory-virus panel and infection-prevention policy because circulating strains, isolation rules and antiviral eligibility change.
- Severe influenza and influenza in clinical-risk groups should receive prompt antiviral treatment under current UKHSA guidance, even when presentation is later than the ideal early window.
Key red flags
Abrupt fever, myalgia, headache and cough progressing to dyspnoea or diffuse infiltrates, with particular concern in pregnancy, older age, immunocompromise and chronic cardiac, neurological or respiratory disease.
Investigation priorities
Identify influenza, SARS-CoV-2, RSV or another virus and guide treatment and infection control.
Management branches
Suspected viral pneumonitis with lower-respiratory symptoms.
- Perform ABCDE assessment, prescribe target-based oxygen, obtain viral samples and apply the current local isolation/PPE pathway without delaying emergency support.
- Assess timing and risk factors for influenza or COVID-specific treatment, and search for focal bacterial infection, embolism, myocarditis or decompensated chronic disease.
Key medicines
OseltamivirA typical adult treatment course is 75 mg orally twice daily for 5 days; severe or immunocompromised cases and renal impairment require current UKHSA/BNF adjustment.
Dexamethasone for hypoxic COVID-196 mg orally or IV once daily for up to 10 days, stopping earlier at discharge, when COVID-19 causes a need for supplemental oxygen.