Management of Rhinosinusitis (Sinusitis): Stepwise Approach from First Stage to Antibiotic Therapy
- Mayta
- Oct 23
- 3 min read
1. Definition and Classification
Rhinosinusitis refers to inflammation of the mucosa of the nasal cavity and paranasal sinuses.It often begins as viral rhinosinusitis and may progress to bacterial sinusitis in a small percentage of cases.
Type | Duration | Typical Cause |
Acute | ≤ 4 weeks | Usually viral; bacterial if severe/persistent |
Subacute | 4–12 weeks | Unresolved infection |
Chronic | > 12 weeks | Multifactorial (inflammation, allergy, biofilm, polyp) |
2. Common Etiologic Agents
Viral (Most Common, ~90%)
Rhinovirus, Influenza, Parainfluenza, Coronavirus
Bacterial (Secondary infection)
Streptococcus pneumoniae
Haemophilus influenzae
Moraxella catarrhalis
3. Diagnostic Criteria: When to Suspect Bacterial Sinusitis
Antibiotics are NOT first-line for all sinusitis.They are reserved for bacterial cases based on these IDSA criteria:
Acute Bacterial Rhinosinusitis (ABRS) criteria
At least one of the following:
Persistent symptoms > 10 days without improvement
Severe symptoms: high fever ≥ 39 °C + purulent nasal discharge + facial pain lasting ≥ 3–4 days
Double sickening: worsening symptoms after initial improvement (after 5–6 days)
If none of these are present → Viral rhinosinusitis → treat supportively only.
4. Stepwise Management Approach
Stage 1: Viral / Early Non-Severe Sinusitis (Day 1–10)
🧠 “Supportive Care First”
A. Non-Pharmacologic Management
Nasal saline irrigation
Isotonic (0.9%) preferred for daily use
Hypertonic (2–3%) short-term use for severe congestion
Clears mucus, allergens, and pathogens
Enhances steroid absorption
Steam inhalation / humidified air→ Relieves congestion and sinus pressure
Adequate hydration→ Thins mucus and improves drainage
Rest and sleep hygiene
B. Pharmacologic Supportive Treatment
Medication | Example & Dose | Role |
Intranasal corticosteroid | Budesonide (Bunase®) 1–2 sprays/nostril OD–BID | Reduces inflammation, edema, and congestion |
Analgesic / Antipyretic | Paracetamol 500 mg q6h prn or Ibuprofen 400 mg tid pc | For facial pain, fever |
Antihistamine (if allergic) | Loratadine 10 mg od or Cetirizine 10 mg od | For rhinorrhea, sneezing |
Decongestant (short-term only) | Oxymetazoline spray bid ≤ 3 days | Opens nasal airway, avoid prolonged use (rebound rhinitis) |
🩸 No antibiotic at this stage.
Stage 2: Bacterial Sinusitis Confirmed or Highly Suspected
🦠 “Start Antibiotic + Continue Supportive”
A. First-line Antibiotic Therapy
Drug | Dose | Duration | Remarks |
Amoxicillin–Clavulanate | 875/125 mg po bid pc | 5–7 days | First choice (covers S. pneumoniae & H. influenzae) |
Amoxicillin | 1 g po tid pc | 7–10 days | If low resistance risk |
Doxycycline (if penicillin-allergic) | 100 mg po bid | 5–7 days | Alternative agent |
Levofloxacin / Moxifloxacin | 500 mg po qd | 5 days | Reserve for resistant or recurrent cases |
❌ Avoid macrolides (Azithromycin, Clarithromycin) — due to high resistance of S. pneumoniae and H. influenzae.
B. Continue Adjunctive Therapies
Nasal saline irrigation (daily)
Intranasal corticosteroid (Budesonide / Mometasone)
Pain control with NSAIDs or acetaminophen
Antihistamines if allergic component present
Stage 3: Non-Responsive or Complicated Sinusitis
🏥 “Re-evaluate and escalate care”
If no improvement after 7 days of ATB or symptoms > 4 weeks:
Reassess diagnosis – exclude dental origin or fungal sinusitis
Obtain CT paranasal sinus for anatomical obstruction (In Thai, we order a film, PNS paranasal sinus)
ENT referral for:
Nasal endoscopy
Possible sinus drainage or culture
Consider a short-course oral corticosteroid if a nasal polyp is present
5. Chronic Rhinosinusitis (>12 weeks)
Usually inflammatory rather than infectious.Mainstay of treatment:
Intranasal corticosteroids daily
Saline irrigation
Treat underlying allergy/asthma
Antibiotics only if acute bacterial exacerbation
If persistent → CT scan → ENT evaluation for Functional Endoscopic Sinus Surgery (FESS)
6. Monitoring and Follow-up
Parameter | Time frame | Action |
Mild viral case | 7–10 days | Continue supportive care |
Bacterial case on ATB | Reassess after 5–7 days | If no response → change antibiotic or ENT referral |
Chronic / recurrent case | 4–6 weeks | ENT assessment ± imaging |
7. Patient Education
✅ Use nasal spray correctly (angle away from septum)
✅ Avoid using decongestant > 3 days
✅ Continue saline irrigation daily
✅ Complete full course of antibiotics
✅ Return if: fever > 39 °C, visual changes, periorbital swelling, or confusion
Clinical Pearls for Exams
>10 days or double sickening = Bacterial sinusitis
First-line antibiotic: Amoxicillin–Clavulanate
Saline + Steroid are foundation for all stages
Do not use macrolides or decongestants long-term
Chronic sinusitis → anti-inflammatory (steroid), not antibiotic
📚 References
IDSA Guidelines for Acute Bacterial Rhinosinusitis in Adults and Children, Clin Infect Dis. 2021
EPOS 2020: European Position Paper on Rhinosinusitis and Nasal Polyps
Thai Clinical Practice Guideline for Rhinosinusitis (2022), Royal College of Otolaryngologists of Thailand
CDC Sinus Infection Treatment Guidelines, 2023
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