What is the treatment plan for viral infection symptoms in an adult?

Treatment of Viral Infection Symptoms in Adults

For most adults with viral respiratory infections, supportive care with symptomatic relief is the primary treatment approach, as antibiotics are ineffective and most viral illnesses are self-limiting within 10-14 days. 1

Initial Assessment and Risk Stratification

When evaluating an adult with viral infection symptoms, immediately determine if this represents:

• Simple viral rhinosinusitis (common cold): Symptoms peak within 3 days and gradually resolve within 10-14 days 1
• Influenza: Requires consideration of antiviral therapy if presenting within 48 hours of symptom onset 2
• Severe viral encephalitis: Requires urgent neurological assessment and empiric acyclovir 1, 3

Red flags requiring immediate escalation include falling level of consciousness, new seizures, new focal neurological signs, persistent high fever >3 days with severe cough, rapid respiratory rate, dyspnea, or mental status changes 1.

Symptomatic Management for Uncomplicated Viral Infections

Analgesics and Antipyretics

• Acetaminophen or ibuprofen for pain, fever, headache, and myalgias 1
• NSAIDs may have particular value in early COVID-19 to address the underlying inflammatory response 4

Nasal Symptoms

• Nasal saline irrigation (physiologic or hypertonic) provides minor symptom improvement with minimal adverse effects 1
• Oral decongestants may provide relief unless contraindicated by hypertension or anxiety 1
• Topical decongestants limited to 3-5 days maximum to avoid rebound congestion 1

Cough and Secretions

• Oral antihistamines may reduce excessive secretions and sneezing based on clinical experience 1
• Guaifenesin and dextromethorphan are commonly used but lack strong efficacy evidence 1

Intranasal Corticosteroids

• May provide modest benefit for nasal congestion and facial pain, though not FDA-approved for acute viral illness 1
• 73% improvement rate versus 66% with placebo at 14-21 days, with rare adverse events 1
• Decision to use should be based on patient preference given small effect size 1

Antiviral Therapy for Influenza

Oseltamivir 75 mg twice daily for 5 days should be initiated within 40-48 hours of symptom onset in adults with confirmed or suspected influenza 2.

• Reduces median time to symptom improvement by 1.3 days in otherwise healthy adults 2
• More rapid cessation of febrile illness in patients with chronic cardiac or respiratory disease 2
• Treatment effect is similar in men and women 2
• In geriatric patients (≥65 years), provides 1-day reduction in time to improvement 2

Management of Severe Viral Encephalitis

If viral encephalitis is suspected (altered consciousness, new seizures, focal neurological signs), immediately initiate IV acyclovir 10 mg/kg every 8 hours while awaiting diagnostic confirmation. 1, 3

Acyclovir Dosing Requirements

• 10 mg/kg IV every 8 hours for HSV encephalitis in adults with normal renal function 3
• Calculate dose based on actual body weight, not fixed dosing 3
• Mandatory dose adjustment for renal impairment: reduce by 50% if creatinine clearance <50 mL/min 3
• Continue for 14-21 days for confirmed HSV encephalitis 1, 3

Duration and Monitoring

• Repeat lumbar puncture at 14-21 days to confirm CSF is HSV PCR-negative 1
• If CSF remains positive, continue IV acyclovir with weekly PCR until negative 1
• Early initiation within 4 days reduces mortality to 8% versus 28% with delayed treatment 3

When to Stop Empiric Acyclovir

Acyclovir can be discontinued if: 1

• Alternative diagnosis is established, OR
• HSV PCR negative on two occasions 24-48 hours apart AND MRI not characteristic for HSV encephalitis, OR
• Single negative HSV PCR >72 hours after symptom onset WITH unaltered consciousness, normal MRI (>72 hours post-onset), and CSF <5×10⁶/L white cells

VZV Encephalitis

• IV acyclovir 10-15 mg/kg three times daily for VZV encephalitis 1
• Consider short course of corticosteroids (prednisolone 60-80 mg daily for 3-5 days) given inflammatory nature 1
• Stronger indication for corticosteroids if vasculitic component present 1
• VZV cerebellitis typically self-limiting and does not require antiviral treatment 1

Critical Care Considerations

Patients with deteriorating consciousness require: 1, 5

• Urgent ICU assessment for airway protection and ventilatory support
• Management of raised intracranial pressure and cerebral perfusion pressure optimization
• Correction of electrolyte imbalances
• Transfer to neurological specialist unit within 24 hours if diagnosis uncertain or patient fails to improve 1, 5
• Access to MRI/CT neuroimaging and EEG within 24-48 hours 1, 5

What NOT to Do

Avoid antibiotics for viral infections as they are ineffective, do not provide symptom relief, and contribute to resistance 1. Discolored nasal discharge reflects neutrophil presence from inflammation, not bacterial infection 1.

Do not use corticosteroids routinely in HSV encephalitis outside of clinical trials, though they may have a role under specialist supervision 1.

Do not use fixed acyclovir doses for serious herpes infections—always calculate based on actual body weight 3.