II. Epidemiology
-
Incidence: 31 Million cases per year in U.S.
- United States clinic office visits: 1%
- Incidence: 14% annually in adults (25% lifetime Incidence)
- Fifth most common indication for Antibiotic prescription in the U.S.
- Sinuses affected
- Maxillary Sinus
- Most commonly infected in adults
- Frontal Sinus
- Next most commonly infected in adults
- Absent in 10% population and very young children
- Higher risk for intracranial spread
- Ethmoid Sinus
- Most commonly infected in children
- Sphenoid Sinus
- Isolated infection is rare
- Higher risk for intracranial spread
- Maxillary Sinus
III. Pathophysiology
- Background
- Viral Upper Respiratory Infections involve sinuses in 90% of cases
- Less than 1% of Upper Respiratory Infections evolve into documented Sinusitis
- Less than 10% of these documented Sinusitis cases are due to Bacterial superinfection
- Initial
- Mucosal inflammation of Paranasal Sinuses and nasal mucosa
- Nasal mucosa and sinus mucosa are contiguous and typically co-inflamed
- Sinus ostia irritation and edema
- Ciliary transport impaired by infection results in stasis of mucous
- Mucosal inflammation of Paranasal Sinuses and nasal mucosa
- Next
- Sinus ostia obstruction and stasis
- Subsequent sinus infection
IV. Types
- Acute Sinusitis
- Symptoms as long as 4 weeks
- Further subdivided into Bacterial or viral
- Subacute Sinusitis
- Symptoms persist between 4 to 12 weeks
-
Chronic Sinusitis
- Persistent Symptoms beyond 12 weeks
- Recurrent Sinusitis
- Four or more episodes per year
- Each episode lasts 7 days or more
- Symptom free intervals last greater than 2 months
V. Risk Factors
- Ciliary Disorder
- Tobacco use or smoke exposure
- Cystic Fibrosis
- Kartagener Syndrome (primary ciliary Dyskinesia)
- Mechanical obstruction
- Nasal Polyps
- Septal deviation
- Hypertrophic middle turbinates or concha bullosa
- Nasal Foreign Body
- Inflammatory disorder
- Granulomatosis with Polyangiitis (previously known as Wegener's Granulomatosis)
- Sarcoidosis
- Mucosal edema and inflammation
- Preceding Upper Respiratory Infection or recurrent Upper Respiratory Infection
- Vasomotor Rhinitis
- Allergic Rhinitis and other hyperreactivity
- Allergens (e.g. pollens, molds, animal dander)
- Air pollutants
- Nonallergic (Samter's Triad)
- Asthma
- Nasal Polyps
- Aspirin sensitivity
- Iatrogenic causes
- Dental Infections and procedures
- Sinus Surgery
- Nasogastric Tubes
- Nasal Packing (e.g. Epistaxis)
- Mechanical Ventilation
- Immune disorder (predisposes to prolonged course, recurrence, fungal and other atypical infections)
- AIDS
- Congenital Hypogammaglobulinemia (IgA or IgG subclass deficiency)
- Post-Transplant with Immunosuppression
- Chemotherapy
- Diabetes Mellitus
- Chronic Corticosteroid use
VI. Etiology
- Viral (most cases, 90 to 98% of all Rhinosinusitis)
- Rhinovirus (most common viral Sinusitis cause)
- Influenza
- Parainfluenza
- Adenovirus
-
Bacterial (superinfection of up to 2% of viral Upper Respiratory Infections)
- Acute Sinusitis
- Chronic Sinusitis
- Anaerobes (>50%)
- Bacteroides
- Anaerobic Gram Positive Cocci
- Fusobacterium species
- Other less common causes
- Hemophilus Influenzae
- Pseudomonas aeruginosa
- Escherichia coli
- Beta-hemolytic Streptococcus (e.g. Streptococcus Pyogenes)
- Neisseria causes
- Staphylococcus aureus
- Not considered a significant cause of acute uncomplicated Sinusitis
- Anaerobes (>50%)
- Fungal (Immunocompromised or Diabetes Mellitus)
- Aspergillus
- Mucormycosis
- Fungus
VII. Symptoms
- Classic Sinus Symptoms
- Sinus "aching" pain or pressure
- Foul Nasal Discharge or postnasal discharge
- Purulent yellow or green Nasal Discharge
- Discharge color does not indicate Bacterial cause
- Discharge for >10 days suggests Bacterial Sinusitis
- Associated Nasal Symptoms
- Decreased Sense of Smell (Hyposmia or Anosmia)
- Halitosis
- Snoring
- Mouth breathing
- Nasal or hyponasal speech
- Generalized symptoms
- Symptoms not correlating with Sinusitis
- Sore Throat (except with postnasal discharge)
- Sneezing
VIII. Symptoms: Red Flags (consider imaging and ENT referral)
- High Fever over 102.2 F (39 C) or peristent fever
- Visual complaints (e.g. Diplopia)
- Periorbital edema or erythema
- Mental status changes
- Severe facial or Dental Pain
- Infraorbital hypesthesia
IX. Signs
- Nasal Mucosa edema and erythema
- Contrast with Allergic Rhinitis (pale, boggy mucosa)
- Nasal exam to view pus discharge from lateral wall
- Instruments
- Nasal speculum (minimal visualization)
- Flexible Nasolaryngoscopy
- Rigid optical scope (Otolaryngology use)
- Middle Meatus (hiatus semilunaris)
- Drains Maxillary, Frontal, and Anterior Ethmoid
- Consider local Topical Decongestant application
- Superior Meatus (Rarely discharge is seen)
- Drains posterior Ethmoid Sinus
- Instruments
- Turbinates enlarged
- Sinus tenderness to percussion
-
Sinus Transillumination in darkened room
- Frontal and Maxillary Sinus
X. Diagnosis: Findings most suggestive of Bacterial cause
- See Sinusitis Prediction Rules
- Symptoms persist beyond 10 to 14 days
- Under 10 days of symptoms, viral Sinusitis predominates
- By day 10, 40% of Sinusitis resolves spontaneously
- Only 0.5% of viral URIs develop into Bacterial Sinusitis
- Symptoms worsen after 5-7 days ("double sickening")
- Typical course: Onset, then improvement, then worse again
- Purulent Nasal Discharge
- Maxillary tooth or facial pain (especially if unilateral)
- Unilateral Maxillary Sinus tenderness
- References
XI. Diagnosis: Infectious Disease Society of America (IDSA)
- Treat as Sinusitis if at least one of 3 criteria present
- Onset with severe signs or symptoms
- High fever (>102.2 F or 39 C) AND
- Purulent nasal drainage or facial pain for at least 3 to 4 consecutive days at the start of the illness
- Persistent Acute Bacterial Rhinosinusitis symptoms >=10 days without clinical improvement
- Double Sickening
- Initial viral Upper Respiratory Infection lasting 5 to 6 days and was improving
- Then, worsening findings (fever, Headache, increased Nasal Discharge) for at least 3 to 4 days
- References
XII. Labs
- Culture of nasal mucosa
- Not cost effective or helpful in management
- Does not correlate with sinus mucosa cultures
- Endoscope directed micro-swab culture
- Swab of hiatus semilunaris
- Protected from nasal contamination
- Accuracy: 80-85% compared with antral puncture
XIII. Imaging
- Indications for Imaging
- Imaging is not needed in routine cases (esp. Acute Sinusitis)
- Does not differentiate viral from Bacterial cause
- Empiric therapy for 1-2 courses is appropriate
- Complicated Sinusitis (esp. Immunocompromised patients)
- Chronic or recurrent Sinusitis
- Sinusitis refractory to maximal medical therapy
- Example: Amoxicillin course for 10 days followed by Levaquin course for 10-14 days
- Imaging is not needed in routine cases (esp. Acute Sinusitis)
-
Sinus XRay (not recommended)
- Single Waters' View XRay is sufficient
- Indication (rarely indicated unless CT not available)
- Complicated Acute Sinusitis
- Suspected Chronic Sinusitis
-
Sinus CT without contrast (gold standard)
- Findings
- Mucosal thickening >5mm is consistent with sinus infection
- Non-contrast CT
- Demonstrates fluid and mucosal edema, as well as bony destruction
- Fat stranding (increased density) may be present in para-sinus spaces
- CT-Contrast CT
- Necrotic tissue and fluid does not contrast enhance
- Inflamed, thickened mucosa contrast enhances
- Mucosa, fluid and soft tissue may be indistinguishable without contrast
- Consider IV contrast in complicated cases (e.g. vascular complications, Cavernous Sinus Thrombosis)
- Indications (cases refractory to maximal medical therapy)
- Define Sinus Anatomy prior to Sinus Surgery
- Osteomeatal complex Occlusion
- Chronic Sinusitis
- Recurrent Sinusitis
- Allergic Fungal Sinusitis
- Findings
- Sinus MRI
- No advantage over Sinus CT except for complicated cases (e.g. neoplasm)
- More False Positive results
- Indications
- Suspected neoplasm
- Orbital or intracranial extension
- Fungal Sinusitis
- Views: T1 Weighted Images with IV gadolinium
- Fluid, air, bone are black
- Fat is white, but black with fat suppression
- Contrast-enhanced mucosa is bright white
- Necrotic tissue will not enhance and will appear as black
- No advantage over Sinus CT except for complicated cases (e.g. neoplasm)
XIV. Complications
- Orbital Cellulitis (and Periorbital Cellulitis)
- Meningitis
- Extradural abscess
-
Subdural Empyema
- Subdural Abscess, especially associated with Frontal Sinusitis
- Brain Abscess
- Pott's Puffy Tumor
- Cavernous Sinus Thrombosis
- Fungal Sinusitis
- Sudden fulminant progression has a high mortality (>50%)
- Risk of intracranial spread (hematogenous or from adjacent bony destruction)
XV. Management
- See Acute Sinusitis Management
- Referral Indications
- See Red Flag Symptoms above
XVI. Reference
- Broder (2018) Crit Dec Emerg Med 32(10): 12-3
- Aring (2011) Am Fam Physician 83(9): 1057-63 [PubMed]
- Aring (2016) Am Fam Physician 94(2): 97-105 [PubMed]
- Chow (2012) Clin Infect Dis 54(8):e72-e112 [PubMed]
- Giebink (1994) Pediatr Infect Dis J 13(suppl 1):S55-8 [PubMed]
- Hadley (1997) Otolaryngol Head Neck Surg 117:S8-S11 [PubMed]
- Lanza (1997) Otolaryngol Head Neck Surg 117:S1-7 [PubMed]
- Masood (2007) Postgrad Med J 83(980): 402–408 +PMID:17551072 [PubMed]
- Osguthorpe (2001) Am Fam Physician 63:69-76 [PubMed]
- Rosenfeld (2007) Otolaryngol Head Neck Surg 137(3 suppl): S1-31 [PubMed]
- Slavin (1991) J Allergy Clin Immunol 88:141-146 [PubMed]
- Williams (1993) JAMA 270:1242-6 [PubMed]