Definition And Classification
Disease Overview
- Inflammation involving mucosal lining paranasal sinuses.
- Preferred terminology acute rhinosinusitis secondary concurrent nasal mucosa involvement.
- Acute: Symptom duration <30 days.
- Subacute: Symptom duration 30-90 days.
- Chronic: Symptom duration >90 days continuous inflammation.
- Recurrent Acute: >=4 distinct episodes annually demonstrating complete inter-episode resolution.
- Acute Bacterial Rhinosinusitis (ABRS): Bacterial superinfection complicating initial viral upper respiratory infection.
Paranasal Sinus Development
Chronological Pneumatization
- Development timeline predicts infection anatomical site based patient age.
- Ethmoid And Maxillary: Present, pneumatized at birth. Constitute primary sinusitis sites infants, toddlers.
- Sphenoid: Pneumatization occurs ages 3-5 years.
- Frontal: Pneumatization begins ages 6-8 years, reaching full development during adolescence. Frontal sinusitis rare children <10 years.
Etiology And Microbiology
Causative Organisms
- Viral Pathogens (Most Common): Rhinovirus, Influenza, Adenovirus, Parainfluenza, Coronavirus.
- Bacterial Pathogens (ABRS): Nontypeable Haemophilus influenzae (~50%), Streptococcus pneumoniae (~30%), Moraxella catarrhalis (~10-20%).
- Pathogen Shifts: Routine pneumococcal conjugate vaccination shifted prevalence favoring nontypeable Haemophilus influenzae primary ABRS pathogen.
- Severe/Complicated Disease Organisms: Staphylococcus aureus (including methicillin-resistant strains), Streptococcus anginosus group, anaerobes.
Pathophysiology And Predisposing Factors
Disease Mechanism
- Infection strictly follows preceding viral upper respiratory infection.
- Viral infection induces mucosal swelling, localized edema.
- Edema obstructs narrow (1-3 mm) ostiomeatal complex governing sinus drainage.
- Nose blowing forcefully propels colonized nasal secretions sterile sinus cavities.
- Impaired mucociliary clearance traps secretions causing profound stasis.
- Resulting hypoxic, static environment selectively favors high-titer bacterial overgrowth.
Predisposing Risk Factors
- Host Factors: Allergic rhinitis (most frequent risk factor).
- Anatomical Defects: Septal deviation, adenoid hypertrophy, nasal polyps, concha bullosa.
- Systemic Conditions: Cystic Fibrosis (bilateral polyps), Primary Ciliary Dyskinesia, primary immunodeficiencies.
- Environmental/Iatrogenic: Tobacco smoke exposure, prolonged nasogastric/nasotracheal intubation blocking sinus ostia.
Clinical Manifestations And Diagnostic Criteria
AAP Diagnostic Criteria (2013)
- Differentiation simple viral infection from ABRS requires strict clinical criteria.
- Diagnosis established presence any one three distinct clinical presentations:
- Persistent Symptoms: Nasal discharge (any quality) or daytime cough >10 days lacking clinical improvement.
- Severe Onset: High fever >=39°C (102.2°F) concurrent purulent nasal discharge lasting minimum 3-4 consecutive days initial illness.
- Worsening Course (Double Sickening): Initial viral symptom improvement followed new-onset fever, severe headache, worsening discharge day 6-7.
Clinical Severity Score
Assessment Metrics
- Total score <8 indicates mild/moderate disease.
- Total score >=8 indicates severe disease.
| Clinical Sign/Symptom | Assigned Points |
|---|
| Facial tenderness | 3 |
| Severe headache (retro-orbital) | 3 |
| Severe abnormal nasal discharge | 2 |
| Fever >=38.5°C | 2 |
| Cough | 2 |
| Mild headache/Minimal discharge/Congestion | 1 Each |
Evaluation And Investigations
Imaging And Laboratory Assessment
- Clinical Diagnosis: Sufficient uncomplicated acute sinusitis.
- Plain Radiographs: Obsolete pediatrics, high false positive/negative rates, not recommended.
- Contrast-Enhanced Computed Tomography (CT): Gold standard delineating sinus anatomy. Indications strictly reserved suspected orbital/intracranial complications, surgical planning, severe recalcitrant disease.
- Microbiological Diagnosis: Sinus aspirate culture represents gold standard. Routine aspiration impractical, strictly reserved nonresponsive, highly immunocompromised patients.
Differential Diagnosis
Alternate Etiologies
- Viral Upper Respiratory Infection: Clear discharge, symptom duration <10 days.
- Allergic Rhinitis: Seasonal variation, profound nasal eosinophilia, transverse nasal crease.
- Nasal Foreign Body: Unilateral foul-smelling purulent discharge.
Complications
Anatomical Vulnerability
- Pediatric sinusitis highly prone anatomical extension secondary extremely thin separating bony walls (lamina papyracea).
Orbital Complications (Chandler Classification)
- Represents most frequent complication, typically originating ethmoiditis.
- Stage I (Preseptal Cellulitis): Eyelid edema, erythema. Intact, normal extraocular movement.
- Stage II (Orbital Cellulitis): Post-septal inflammation. Proptosis, chemosis, marked ophthalmoplegia.
- Stage III (Subperiosteal Abscess): Purulent collection between lamina papyracea, periorbita. Globe displaced laterally/downward.
- Stage IV (Orbital Abscess): Purulent collection within intraorbital fat. Imposes severe visual threat.
- Stage V (Cavernous Sinus Thrombosis): Bilateral progression, cranial nerve III, IV, VI palsies.
Intracranial And Osseous Complications
- Intracranial Spread: Epidural/Subdural empyema, severe meningitis, brain abscess. Requires emergent broad-spectrum intravenous coverage (Cefotaxime/Ceftriaxone plus Vancomycin, Metronidazole).
- Osseous Spread: Pott Puffy Tumor (frontal bone osteomyelitis producing doughy subgaleal forehead swelling).
Management Strategies
Medical Therapy Approach
- Watchful Waiting: Observation 3 additional days permissible strictly patients displaying persistent criteria (Criterion 1) lacking severity.
- Immediate Pharmacotherapy: Required children exhibiting severe onset or double sickening criteria.
Antibiotic Selection
- First-Line Therapy: Amoxicillin-clavulanate represents drug choice.
- Mild/Moderate Disease: Low-dose Amoxicillin-clavulanate (45 mg/kg/day amoxicillin component divided twice daily).
- Severe Disease/High Resistance Risk: High-dose Amoxicillin-clavulanate (80-90 mg/kg/day amoxicillin component divided twice daily).
- Penicillin Allergy (Type 1 Hypersensitivity): Levofloxacin (10-20 mg/kg/day).
- Penicillin Allergy (Non-Type 1 Hypersensitivity): Cefpodoxime, Cefdinir.
- Severe/Hospitalized Cases: Intravenous Ampicillin-sulbactam, Ceftriaxone, Levofloxacin.
- Treatment Duration: 10-14 days standard, alternatively 7 days post-complete symptom resolution.
Adjuvant And Surgical Therapy
- Adjuvant Measures: Normal saline irrigation beneficial clearing viscous secretions. Intranasal steroids offer modest benefit primarily concurrent allergic rhinitis.
- Contraindicated Adjuvants: Decongestants, antihistamines strictly NOT recommended, severely thicken secretions impairing clearance.
- Surgical Intervention: Functional Endoscopic Sinus Surgery (FESS) establishes drainage/ventilation. Indications include Chandler Stage III+ orbital complications, intracranial extension, failure maximal medical therapy, underlying severe anatomical defects.