Acute bacterial sinusitis

Audience: Patients and providers
Status: Clinical guide · patient + provider
Last updated: 2026-03-09

1. Clinical overview

Acute bacterial sinusitis is a bacterial upper-airway infection that is usually suspected when symptoms persist beyond a typical viral course, present severely at onset, or worsen again after initial improvement.

2. Common causes and risk factors

Most sinusitis is viral; bacterial disease is a minority subset.
Bacterial concern increases with persistent, severe, or worsening “double-sickening” course.

3. Typical symptoms

Facial pressure, purulent nasal drainage, congestion, reduced smell, fever in severe cases.

4. Diagnosis and evaluation

Confirm diagnosis with guideline-based history, exam, and indicated testing.
Screen for severity, complications, and high-risk comorbid conditions.
Identify social or access barriers that could affect treatment success.

5. Treatment (non-pharmacologic)

Hydration, saline irrigation, analgesics, and symptom-directed care.
Avoid unnecessary antibiotics for likely viral illness.

6. Treatment (pharmacologic)

First-line therapy is commonly amoxicillin/clavulanate when bacterial criteria are met.
Doxycycline is a common alternative in penicillin-allergic adults; broader options depend on severity and prior antibiotic exposure.
Keep duration short and guideline-concordant rather than defaulting to prolonged antibiotic courses.

7. Monitoring and follow-up

Expected symptom improvement within days; escalate if orbital/CNS warning signs.

8. Practical counseling points

Give patients a clear “what to do today / when to call / when to seek urgent care” plan.
Use teach-back to confirm understanding of treatment goals and medication instructions.
Simplify regimens when possible to improve adherence and outcomes.

9. Red flags and escalation

Escalate care urgently for severe or rapidly worsening symptoms.
Reassess diagnosis if expected response does not occur within the anticipated timeline.

10. Guideline references

Note: Educational guide only; not a substitute for individualized medical care.