Management of Rhinosinusitis (Sinusitis): Stepwise Approach from First Stage to Antibiotic Therapy

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)

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2. Common Etiologic Agents

Viral (Most Common, ~90%)

• Rhinovirus, Influenza, Parainfluenza, Coronavirus

Bacterial (Secondary infection)

• Streptococcus pneumoniae

• Haemophilus influenzae

• Moraxella catarrhalis
  

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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:

1. Persistent symptoms > 10 days without improvement

2. Severe symptoms: high fever ≥ 39 °C + purulent nasal discharge + facial pain lasting ≥ 3–4 days

3. Double sickening: worsening symptoms after initial improvement (after 5–6 days)

If none of these are present → Viral rhinosinusitis → treat supportively only.

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4. Stepwise Management Approach

Stage 1: Viral / Early Non-Severe Sinusitis (Day 1–10)

🧠 “Supportive Care First”

A. Non-Pharmacologic Management

1. 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

2. Steam inhalation / humidified air→ Relieves congestion and sinus pressure

3. Adequate hydration→ Thins mucus and improves drainage

4. 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:

1. Reassess diagnosis – exclude dental origin or fungal sinusitis

2. Obtain CT paranasal sinus for anatomical obstruction (In Thai, we order a film, PNS paranasal sinus)

3. ENT referral for:

   • Nasal endoscopy

   • Possible sinus drainage or culture

4. Consider a short-course oral corticosteroid if a nasal polyp is present
   

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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)

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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

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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

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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

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📚 References

1. IDSA Guidelines for Acute Bacterial Rhinosinusitis in Adults and Children, Clin Infect Dis. 2021

2. EPOS 2020: European Position Paper on Rhinosinusitis and Nasal Polyps

3. Thai Clinical Practice Guideline for Rhinosinusitis (2022), Royal College of Otolaryngologists of Thailand

4. CDC Sinus Infection Treatment Guidelines, 2023