What is the treatment for a patient with influenza and urticaria?

Treatment of Influenza with Urticaria

For patients with influenza and urticaria, the recommended treatment approach includes antiviral therapy with oseltamivir (75mg twice daily for 5 days) for the influenza infection, along with antihistamines for urticaria management. 1, 2

Antiviral Treatment for Influenza

Indications for Treatment

• Start antiviral treatment as soon as possible for patients with:
  • Acute influenza-like illness
  • Fever (>38°C in adults)
  • Symptoms present for 48 hours or less 1

Antiviral Medication

• First-line therapy: Oseltamivir 75 mg orally twice daily for 5 days 1, 2

  • Dose reduction to 75 mg once daily if creatinine clearance is less than 30 ml/minute 1
  • Earlier administration increases therapeutic benefits and reduces illness duration 3
  • Take with food to enhance tolerability and reduce nausea/vomiting 4

• Special considerations:

  • Hospitalized patients with severe illness may benefit from antiviral treatment even if started more than 48 hours after symptom onset 2
  • Immunocompromised patients may benefit from treatment despite lack of documented fever 1

Management of Urticaria

First-line Treatment

• H1-antihistamines: Start with standard doses of second-generation antihistamines
  • Options include cetirizine, loratadine, or fexofenadine
  • These medications are non-sedating and do not interact with oseltamivir 5

For Refractory Cases

• Consider increasing the antihistamine dose (up to 4x standard dose) if response is inadequate
• For severe or persistent urticaria, a short course of oral corticosteroids may be considered
  • Caution: Corticosteroids should be used judiciously in influenza patients as they may potentially worsen outcomes 2

Monitoring and Follow-up

Clinical Monitoring

• Monitor temperature, respiratory rate, pulse, blood pressure, mental status, and oxygen saturation 1, 2
• Watch for signs of:
  • Respiratory deterioration (increasing dyspnoea)
  • Recrudescent fever
  • Development of pneumonia 1

Indications for Hospital Referral

• Consider hospital admission if two or more of the following are present:
  • Temperature >37.8°C
  • Heart rate >100/min
  • Respiratory rate >24/min
  • Systolic blood pressure <90 mmHg
  • Oxygen saturation <90%
  • Severe or worsening urticaria not responding to treatment 1, 2

Special Considerations

Antibiotic Use

• Antibiotics are not routinely required for influenza without pneumonia 1
• Consider antibiotics only if:
  • Patient develops worsening symptoms (recrudescent fever or increasing dyspnoea)
  • Lower respiratory features are present in high-risk patients
  • Evidence of bacterial co-infection 1

Potential Drug Interactions

• Oseltamivir has a low potential for drug interactions, making it suitable for patients on concomitant medications 5
• Monitor for potential exacerbation of urticaria with certain medications

Common Pitfalls to Avoid

1. Delayed antiviral treatment: Starting oseltamivir within 12 hours of symptom onset can reduce illness duration by up to 74.6 hours compared to starting at 48 hours 3

2. Overlooking hydration: Ensure adequate fluid intake to prevent dehydration, particularly important in patients with fever 2

3. Inappropriate antibiotic use: Avoid unnecessary antibiotics in uncomplicated influenza without evidence of bacterial infection 1

4. Ignoring worsening symptoms: Patients should be advised to seek immediate medical attention if symptoms worsen despite treatment 2

5. Missing influenza-related complications: Monitor for complications such as pneumonia, especially in patients with persistent or recurrent fever 1