Chronic Maxillary Sinusitis - A Comprehensive ENT Review

Definition

• Mucopurulent nasal discharge (anterior or posterior)
• Nasal obstruction or congestion
• Facial pain, pressure, or fullness (maxillary/cheek region)
• Decreased or absent sense of smell (hyposmia/anosmia)

• Polyps in the nasal cavity or middle meatus on endoscopy or anterior rhinoscopy
• Purulence or edema in the middle meatus or anterior ethmoid cavity
• Radiographic (CT) evidence of mucosal thickening, edema, or sinus opacification

K.J. Lee's Essential Otolaryngology, p. 544-545

Etiology

Primary Etiological Factors

• Septal deviation
• Turbinate hypertrophy (inferior or middle)
• Middle turbinate concha bullosa
• Paradoxical turbinate curvature
• Prominent agger nasi cell, Haller cells (infraorbital ethmoid cells)
• Prominent ethmoid bulla
• Pneumatization or inversion of the uncinate process
• Accessory maxillary ostia causing mucus recirculation

• Tooth root/periapical abscesses of upper posterior teeth (premolars, molars)
• Oroantral fistula
• Post-oral surgical infections (e.g., dental implants)
• Generally resolves with treatment of the offending tooth combined with sinus management

• Ciliary beat frequency normally 7-20 Hz; impairment leads to stasis of secretions and secondary bacterial colonization
• Causes: infection, inflammation, toxins, occupational exposures, cigarette smoke, bacterial toxins (especially Staphylococcus), surgical trauma/mucosal stripping, genetic defects (primary ciliary dyskinesia - PCD)
• Mucus viscosity changes: dehydration; cystic fibrosis (thick mucus due to CFTR channel dysfunction, Cl- transport alteration)

• Contain living bacteria colonies that evade host defenses
• Show altered phenotype with atypical growth and gene transcription
• Demonstrate decreased susceptibility to systemic and local antibiotic therapy
• Elicit considerable immunologic reaction
• Especially implicated in medically recalcitrant CRS and revision surgical cases

• Mycetoma/fungal ball (non-invasive)
• Allergic Fungal Sinusitis (AFS): defined by Bent and Kuhn criteria (Type I hypersensitivity, nasal polyposis, characteristic CT findings, eosinophilic mucin with fungal hyphae, positive fungal stain/culture)
• Chronic invasive fungal sinusitis

• Asthma: 84-100% of patients with severe asthma have abnormal sinus CTs. The unified airway concept - CRS and asthma frequently coexist and influence each other
• AERD (Aspirin-Exacerbated Respiratory Disease / Samter's Triad): Aspirin inhibits COX-1 → shunts arachidonic acid to lipoxygenase pathway → excess leukotriene C4/D4/E4 → bronchoconstriction, nasal polyps, sinusitis
• Allergy/Atopy: IgE-mediated inflammation, mast cell degranulation, eosinophilia
• Immunodeficiency: CVID, HIV, IgA/IgG/IgM deficiency, specific antibody deficiency, IgG subclass deficiency, chronic steroid use, chemotherapy, uncontrolled diabetes
• Genetic: Cystic fibrosis, Kartagener syndrome (situs inversus + CRS + bronchiectasis), Primary Ciliary Dyskinesia (PCD)
• Reflux (LPR/GERD): Acid reflux may trigger/worsen sinonasal inflammation (supported by recent meta-analyses - PMID 41447676)
• Rheumatologic disorders: Association recently confirmed in systematic review (PMID 40911435)

K.J. Lee's Essential Otolaryngology, pp. 545-549; Harrison's Principles of Internal Medicine 22e, p. 299

Subtypes of Chronic Sinusitis (Clinical Classification)

Harrison's Principles of Internal Medicine 22e, pp. 299-300; K.J. Lee's Essential Otolaryngology, p. 545

Etiopathogenesis of Chronic Sinusitis (In Detail)

Step 1: Initiating Events

• Viral URTI causes mucosal edema and ciliary dysfunction
• Allergy, pollutants, or irritants cause mucosal inflammation
• Anatomic narrowing of the OMC (even without complete obstruction)

Step 2: Osteomeatal Complex Compromise

• Sinus ostia become obstructed
• Negative pressure develops within the sinus
• Mucociliary clearance becomes impaired
• Oxygen tension drops (hypoxia develops)

Step 3: Bacterial Overgrowth and Biofilm Formation

• Inspissated secretions and hypoxia in the occluded sinus promote bacterial growth
• Bacteria secrete inflammatory mediators and toxins directly damaging ciliated respiratory epithelium
• Further decreased mucociliary clearance creates a vicious cycle
• Biofilm formation (S. aureus, P. aeruginosa) makes bacteria resistant to host defenses and antibiotics

Step 4: Bacterial Superantigen Mechanism

• S. aureus secretes exotoxins (superantigens) that bind MHC-II on antigen-presenting cells and T-cell receptors simultaneously
• This activates up to 30% of the T-lymphocyte pool (vs. normal <0.01%)
• Massive TH2 cytokine release follows
• Activation of CD4+ and CD8+ cells together → TH2 cytokine release → eosinophil recruitment, mast cell degranulation → generation of nasal polyps

Step 5: Sustained Inflammation

• Eosinophilic infiltration, tissue remodeling, and goblet cell hyperplasia
• Mucus gland hypertrophy and submucosal edema
• Osteitis: neo-osteogenesis and bony remodeling in refractory CRS - associated with greater chance of recurrent disease and poor surgical outcomes
• Microbiome diversity decreases (analogous to gut dysbiosis in IBD); this may perpetuate inflammation

Step 6: United Airway Disease

• Nasal inflammation triggers bronchial hyper-reactivity via the "naso-bronchial reflex" and systemic cytokine spillover
• 84-100% of severe asthmatics have abnormal sinus CTs
• Treating CRS improves asthma control, and vice versa

K.J. Lee's Essential Otolaryngology, pp. 545-548

Pathology (Histopathological Changes)

• Mucosal edema, hyperemia, and thickening
• Mucopurulent secretions
• Polypoid degeneration of mucosa
• Goblet cell hyperplasia
• Inspissated/crusted secretions

• Epithelium: Ciliated columnar (respiratory) epithelium replaced by squamous metaplasia or goblet cell hyperplasia
• Submucosa: Edematous, fibrous infiltration, dilated mucous glands
• Inflammatory infiltrate: Eosinophils predominate (especially in CRSwNP and atopic disease); neutrophils in CRSsNP; lymphocytes and plasma cells
• Vascular changes: Angiogenesis, venous congestion
• Osteitis: Neo-osteogenesis, lamellar bone thickening, Haversian canal involvement in refractory cases
• Biofilms: Polysaccharide matrices on mucosal surfaces (identified on electron microscopy)

Clinical Features

Symptoms

1. Facial pain/pressure/fullness: Characteristically felt over the cheek/infraorbital region, may radiate to upper teeth; worse on bending forward
2. Nasal discharge: Mucopurulent, anterior (blowing nose) or posterior (postnasal drip)
3. Nasal congestion/obstruction: Unilateral or bilateral
4. Hyposmia or anosmia: Particularly prominent in CRSwNP; may be the chief complaint

• Fatigue and malaise (hallmark of chronic disease)
• Ear pressure or fullness
• Hoarseness (from postnasal drip)
• Cough (especially nocturnal, from postnasal drainage)
• Halitosis (fetor ex ore/nasi)
• Maxillary toothache (especially premolars/molars - referred from sinus floor)
• Headache (frontal/vertex in severe cases)

Signs

• Mucopurulent discharge in the middle meatus (pathognomonic sign)
• Mucosal edema and pallor or erythema
• Nasal polyps (pale/grey-white, grape-like, non-tender, non-bleeding masses) in middle meatus
• Deviated nasal septum or turbinate hypertrophy

• Purulence or edema in the middle meatus
• Polyps or polypoid change
• Assessment of OMC and maxillary sinus ostium
• Guided culture from middle meatus for bacteriology

Investigations

Imaging

• Modality of choice for CRS evaluation
• Non-contrast CT using bone algorithm and bone windows
• Findings: mucosal thickening, sinus opacification, air-fluid levels, OMC obstruction, polyps, bony changes
• Performed at least 4 weeks after maximal medical therapy to avoid over-diagnosing based on acute inflammation
• In AFS: areas of increased attenuation/density due to ferromagnetic elements from fungi; bony erosion or expansion

• Preferred for suspected intracranial extension, soft tissue assessment, distinguishing secretions from tumors
• Gadolinium-enhanced MRI is preferred for invasive fungal sinusitis

Microbiological

• Endoscopy-guided middle meatal swab or culture - more accurate than nasal swabs
• Antral washout and aspiration: gold standard specimen for bacteriology
• Fungal staining and culture where indicated

Other Investigations

• Allergy testing: Skin prick test, RAST/specific IgE for atopic patients
• Saccharin test / nasal nitric oxide: Screening for mucociliary dysfunction
• Ciliary biopsy and electron microscopy: For suspected PCD
• Sweat chloride test / CFTR gene analysis: For suspected cystic fibrosis
• Immunoglobulin levels: For suspected immunodeficiency (IgG, IgA, IgM, IgG subclasses)
• Nasal cytology: Eosinophil counts

Management

Principles

1. Reduce mucosal inflammation
2. Restore sinus ventilation and mucociliary drainage
3. Eradicate infection
4. Manage predisposing factors and comorbidities
5. Prevent complications and recurrence

Step 1: Avoidance of Triggers

• Allergens (dust mites, mold, animal dander)
• Tobacco smoke (active and passive)
• Occupational exposures
• Irritants and pollutants

Step 2: Medical Treatment

A. Saline Irrigation

• Isotonic or hypertonic nasal saline sprays/washes (nasal lavage, Neti pot)
• Higher-volume saline washes are more effective than sprays
• Mechanical effect: displaces allergens, thins and mobilizes secretions
• Reaches frontal and sphenoid sinuses better than sprays

B. Intranasal Corticosteroids (INCS) - Mainstay of Treatment

• Available agents: Fluticasone, mometasone, budesonide (budesonide > fluticasone > mometasone in systemic absorption)
• Mechanism: Reduce mucosal edema, decrease polyp size, inhibit eosinophil recruitment
• Delivery: Spray bottle or large-volume budesonide rinses (more effective for deeper sinuses)
• Budesonide is safe in pregnancy (Category B)
• Side effects: Epistaxis, mucosal thinning, dry mucosa

C. Oral Corticosteroids

• Short course 2-3 weeks for CRS unresponsive to intranasal steroids, especially in CRSwNP
• Reduces polyp burden; may be used perioperatively (5-7 days before surgery to improve the operative field)
• Long-term use avoided due to systemic side effects

D. Antibiotic Therapy

• Culture-directed antibiotics whenever possible (endoscopy-guided middle meatal culture)
• Broad-spectrum empirical options: amoxicillin-clavulanate, 3rd-generation cephalosporins, respiratory fluoroquinolones, tetracyclines, macrolides
• Long-term macrolides (clarithromycin, roxithromycin) for 3 months - have both bacteriostatic AND anti-inflammatory properties; modest quality evidence supports this approach
• Doxycycline - downregulates inflammatory factors; beneficial in CRSwNP as well

E. Symptomatic Treatment

• Mucolytics: Carbocisteine, guaifenesin - thin secretions, improve mucociliary clearance
• Antihistamines: For patients with allergic component (topical or systemic)
• Decongestants: Oral (pseudoephedrine) or intranasal (oxymetazoline) - short-term use only; avoid prolonged use of topical decongestants (rhinitis medicamentosa risk)
• Leukotriene antagonists: Montelukast - helpful in allergic and AERD-associated CRS
• Aspirin desensitization + zileuton: For AERD (Samter's triad)

F. Immunotherapy

• Allergen-specific immunotherapy for patients with confirmed inhalant allergy
• Benefit in CRS with allergic component

G. Biologic Therapies (Modern Additions)

• Dupilumab (anti-IL-4Ra): FDA-approved for CRSwNP; reduces polyp size and improves symptoms
• Mepolizumab (anti-IL-5), Benralizumab (anti-IL-5Ra): For eosinophilic CRSwNP
• Indicated for severe, refractory CRSwNP unresponsive to maximal medical therapy

H. Management of Comorbidities

• Asthma: Treating CRS improves asthma control and vice versa; consulting pulmonologist
• GERD/LPR: Antireflux therapy (PPI) may benefit CRS
• Immunodeficiency: IVIG replacement therapy for CVID and specific antibody deficiency
• CF: CFTR modulators (ivacaftor, elexacaftor/tezacaftor) + sinonasal irrigations

Step 3: Surgical Treatment

Indications for Surgery

• Diffuse nasal polyposis unresponsive to medical therapy
• Suspected or confirmed fungal sinusitis
• Mucocele formation
• Persistent CT/endoscopic evidence of mucosal disease despite maximal medical therapy
• Significant reduction in quality of life unresponsive to medical management
• Orbital or intracranial extension (urgent)
• Neoplasm requiring biopsy or excision

• Patient must meet diagnostic criteria for CRS
• Must have had a trial of maximal medical therapy
• Persistent evidence of mucosal disease (radiographic or endoscopic)
• Preoperative CT should be done at least 4 weeks after medical therapy onset
• Smoking cessation strongly encouraged (increases scarring, worsens outcomes)
• Alternative diagnoses (rheumatologic, immunologic, neoplastic) explored and addressed
• Patient counseled about possible disease recurrence and revision surgery

Surgical Options

• Removal of disease (polyps, osteitic bone)
• Re-establishment of sinus aeration and drainage
• Improvement of postoperative topical drug delivery
• Preserve mucoperiosteium; limit mucosal stripping

• Through inferior meatus under inferior turbinate
• Diagnostic and therapeutic: irrigation of sinus, bacteriology samples
• More suited for acute-on-chronic disease, less used for definitive chronic management

• External approach through the anterior maxillary sinus wall via buccal sulcus incision
• Removes all diseased mucosa
• Creates a large nasoantral window in inferior meatus
• Now largely replaced by FESS
• Still used for: recurrent disease after FESS, maxillary sinus tumors, retrieval of foreign bodies, dental implant complications

• Minimally invasive catheter-based dilation of sinus ostia
• Preserves mucosa; no tissue removal
• Limited data for CRS with polyposis; better for mild-moderate focal disease

• Oral steroids 5-7 days preoperatively (improves operative field, reduces polyp burden)
• Controlled hypotension intraoperatively
• Total intravenous anesthesia (TIVA) reduces bleeding
• Head elevation intraoperatively
• Warm saline irrigation to reduce bleeding
• Postoperative nasal saline irrigations, topical steroids, and endoscopic debridement at follow-up

• Surgery produces good results; medical therapy classically ineffective
• Perioperative glucocorticoids essential
• Antifungal agents have NOT shown benefit in any CRS subtype

Step 4: Postoperative Follow-up

• Regular endoscopic nasal toilet and debridement
• Continued topical steroid + saline irrigations
• Culture-directed antibiotics for infected cases
• Monitoring for recurrence of polyps
• Management of comorbid allergic and pulmonary disease

Complications of Chronic Maxillary Sinusitis

• Mucocele/pyocele formation
• Osteitis and bony erosion
• Imploding maxillary sinus (silent sinus syndrome)

• Orbital cellulitis
• Subperiosteal abscess
• Orbital abscess

• Meningitis
• Epidural/subdural/cerebral abscess
• Cavernous sinus thrombosis
• Superior sagittal sinus thrombosis

• Septicemia
• Osteomyelitis of maxilla/frontal bone

Key Points Summary

• K.J. Lee's Essential Otolaryngology (10e), pp. 544-553
• Cummings Otolaryngology Head and Neck Surgery
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery, Vol. 1
• Harrison's Principles of Internal Medicine, 22e, pp. 299-300