A. Causes of Acute Sinusitis [1]

1. Viruses believed to be most common cause of acute sinusitis
   1. Often follows upper respiratory infection (URI)
   2. Many initial sinus cultures are negative for bacterial (or fungal) organisms)
   3. Viral URI may lead to bacterial superinfection including bacterial sinusitis
2. Common bacterial causes: S. pneumoniae and H. influenza
3. Occasional bacterial causes: B. catarrhalis, Streptococcus pyogenes, anaerobes
4. Strong association with presence of nasal polyps
5. Symptoms are most predictive of disease

B. Causes of Chronic Sinusitis

1. Culture of Organisms [3]
   1. 30% showed no growth - may represent sterile fluid due to mucous cell hypersecretion
   2. 38% were Gram positive cocci, mainly Staph aureus and Strep pneumoniae
   3. 15% were Gram negative rods
   4. Fungal forms in 1.7%
   5. H. influenza and Branhamella (Moraxella) catarrhalis were often penicillinase producing
2. Chronic sinusitis may be singificantly associated with drainage problems (and inflammation)
3. Strong association of nasal polyps with chronic sinusitis, asthma, and allergies
4. Nasal Polyps
   1. Outgrowths of nasal mucosa of varying appearance
   2. Located on lateral wall of the nose
   3. Usually in middle meatus or along middle and superior turbinates
   4. Most polyps originate from ethmoid sinuses
   5. More common in men than women (2:1)
   6. Polyps composed of edematous fluid with sparse fibrous cells and some mucous glands
   7. Eosinophils present in large numbers in ~75% of cases
   8. Histamine and IgE levels are elevated in polyp fluid
5. Nasal masses can cause obstruction, sinusitis, including angiofibroma, sarcoma, birous dysplasia, neuroblastoma, lymphoma, osteosarcoma, chondrosarcoma [17]
6. Chronic sinusitis is associated with various mutations of cystic fibrosis transmembrane regulator (CFTR) [9,10]

C. Nosocomial Sinusitis [4]

1. Very high incidence with nasal intubation or nasogastric tubes
2. Use of orogastric tubes over nasogastric tubes has greatly reduced incidence (95% to 23%)
3. Cultures often contain a variety of organisms
4. Gram negatives: Pseudomonas, Klebsiella, Enterobacter, Proteus, E. coli
5. Should be considered as a cause of fever in critically ill patients

D. Fungal Sinusitis [2]

1. Noninvasive and invasive forms
2. Should be considered in all patients with chronic sinusitis
3. Noninvasive Fungal Sinusitis
   1. Organisms include Aspergillus, Fusarium, and Dematiaceous molds
   2. Especially in persons with allergic rhinitis, asthma, nasal polyps, sinus calcifications
   3. Intractable symptoms despite adequate treatment for bacterial sinusitis
   4. Surgery nearly always necessary to establish drainage and remove impacted material
4. Invasive Fungal Sinusitis [11]
   1. Especially in immunocompromised patients
   2. Most cases of invasive fungal sinusitis occur in diabetics
   3. Hemochromatosis, protein malnutrition, or neutropenia also risk factors
   4. Zygomycetes (rhizopus, Cunninghamella), Aspergillus, Fusarium, Pseudoallereschia
   5. Emergency surgery required to remove necrotic tissue
   6. Osteomyelitis is a frequent complication of invasive infection
   7. Amphotericin B is indicated with possible long term oral antifungal suppression
   8. Reverse immunosuppression if possible

E. Orbital Complications

1. Periorbital and orbital cellulitis
2. Inflammatory edema
3. Subperiosteal and orbital abscess
4. Optic neuritis with acute visual changes
5. Osteomyelitis
6. Cavernous sinus thrombosis

F. Intracranial Complications

1. Meningitis - most common
2. Epidural or Brain parenchymal abscess
3. Subdural empyema

G. Diagnosis

1. Typical Symptoms
   1. Symptoms after URI
   2. Pain on bending forward
   3. Maxillary Toothache
   4. Nasal Obstruction
   5. Nasal Discharge
   6. Pain increased with chewing
   7. Non-specific: cough, headache, fever
2. Suggestive of Bacterial Infection
   1. Purulent rhinorrhea
   2. Unilateral predominance of pain (usually over maxilla)
   3. Poor response to nasal decongestants
   4. Significant fever
3. Symptoms are most important for diagnosis of acute sinusitis
4. Abnormal transillumination may be useful
5. Plain Radiography [12,13]
   1. May detect maxillary, frontal disease
   2. Less sensitive for disease of the sphenoid or ethmoid
   3. Clinical symptoms are generally at least as good as plain radiography for diagnosis
   4. Sinus radiography is not recommended for diagnosis of acute uncomplicated sinusitis
6. Computerized Tomographic (CT) Scans [15]
   1. Use less radiation and detect maxillary, sphenoidal, frontal and ethmoidal disease
   2. Increased sensitivity for mucosal thickening over plain radiographs
   3. Can also discover non-sinusitis pathologies
   4. Are considered gold standard for confirmation of diagnosis (with history and physical)
   5. Sensitivity is 80-95% and specificity 41-59% for chronic rhinosinusitis [15]
   6. CT scan generally not required for acute sinusitis diagnosis or treatment

G. Treatment

1. Acute Sinusitis - First Episode
   1. Nasal decongestant 3 days - prefer strong topical agent such as oxymetazoline (Afrin®)
   2. Use of nasal decongestant for >3 days often leads to rebound nasal obstruction
   3. Rebound nasal obstruction can be reduced or eliminated with nasal glucocorticoid inhaler
   4. Consider oral decongestant (such as pseudoephedrine)
   5. Nonsteroidal anti-inflammatory drugs (such as ibuprofen 400-600mg tid-qid) reduce pain
   6. Avoid drying anti-histamines and other anticholinergic agents
   7. Nasal glucocorticoid inhaler should be considered in patients with allergies
   8. Second generation antihistamines such as loratadine (Claritin®) useful in allergic patients
   9. Amoxicillin 500mg po tid x 7 days or budesonide topical 200µg bid x 10 days, or both together no better than placebo in typical first episode acute sinusitis [6]
   10. Budesonide topical 200µg x 10 days likely better than placebo for less severe sinusitis [6]
2. Antibiotics [12]
   1. Acute bacterial sinusitis does not require antibacterials unless moderate or severe [5,6,7]
   2. Patients with severe or persistent moderate symptoms should probably be treated [7]
   3. Antibiotics for 10 days benefit patients with acute moderate or severe sinusitis [1]
   4. Amoxicillin 500mg po tid x 7 days ± budesonide topical 200µg bid x 10 days was no better than placebo in typical first episode acute sinusitis [6]
   5. If antibiotics used, narrow spectrum agents are recommended first line
   6. Penicillin V or amoxicillin as good as other antibiotics and better than placebo [8]
   7. First Choice Antibiotic: amoxicillin, TMP/SMX (Bactrim®, Septra®), loracarbef (Lorabid®), amoxicillin-clavulanate (Augmentin®), cefuroxime (Ceftin®), doxycycline
   8. Other second generation cephalosporins, fluoroquinolones, macrolides also active
   9. Azithromycin 500mg qd for 3 days has shown good efficacy and is reasonable 2nd line
   10. Single dose extended release azithromycin (Zmax®, 2gm po x 1) approved for acute sinusitis [16]
   11. Overuse of antibiotics with viral sinusitis can lead to bacterial resistance
3. Recurrent Episode of Acute Sinusitis
   1. Treatment types as above but courses are usually longer
   2. Topical nasal decongestant should be 3 days only (due to rebound effects) [14]
   3. Nasal glucocorticoid inhaler such as fluticasone improves success, reduces symptoms [14]
   4. Antibiotics such as doxycycline, Augmentin®, cefuroxime, clarithromycin for 3-4 weeks
   5. Unclear if antibiotics used for initial episode of acute sinusitis prevent future episodes
4. Chronic Sinusitis
   1. 6 weeks Augmentin® or second generation cephalosporin with long term inhaled steroid
   2. Oral decongestants and mucolytics of some benefit (eg. Entex LA®)
   3. Consider surgical drainage if refractory
   4. Consider surgical correction (such as Antrostomy): cure rates as high as ~60%
   5. Drainage material must be cultured and stained for organisms to target therapy
5. Nosocomial Sinusitis
   1. Resistant gram negative and anaerobic organisms often found
   2. Imipenem covers most of these organisms
   3. Alternative is Timentin® or Zosyn® or Ceftazidime + Metronidazole
   4. Drainage should be considered
6. Nasal polyps are treated with medications as above; surgery may be required

H. Nasal Glucocorticoid Inhalers

1. Generally indicated for chronic and subacute (? acute) sinusitis
2. Decrease local inflammation, allowing sinus drainage to increase
3. May be used with antibiotics safely in infectious sinusitis
4. Also indicated for nasal polyps
5. Agents are fairly equivalent, but dexamethosone and fluticasone may work more quickly
6. Beclomethasone - Beconase®, Vancenase® 2-4 puffs each nostril bid to tid
7. Triamcinolone - Nasacort®; 2 puffs each nostril qd to bid
8. Dexamethasone - Dexacort®; 2 puffs each nostril bid to tid
9. Fluticasone - Flonase®; 2 puffs each nostril bid to tid
10. Glucocorticoid - Antibiotic Solution
    1. This has been used by several physicians with excellent results
    2. Should not be used for more than 5 days in a row, or more than 10 days per month
    3. Ocean Spray® 32cc + 8mg dexamethasone + 40mg gentamicin
    4. May be mixed by most pharmacies
    5. May be used concommitantly with venoconstrictors such as oxymetazoline

References

1. Piccirillo JF. 2004. NEJM. 351(9):902
2. DeShazo RD, Chapin K, Swain RE. 1997. NEJM. 337(4):254
3. Bhattacharyya N and Kepnes LJ. 2003. Arch Otolaryngol Head Neck Surg. 125:1117
4. Vincent JL. 2003. Lancet. 361(9374):2068
5. Ah-See KW and Evans AS. 2007. Brit Med J. 334(9589):358
6. Williamson IG, Rumsby K, Benge S, et al. 2007. JAMA. 298(21):2487
7. Young J, Sutter AD, Merenstein D, et al. 2008. Lancet. 371(9616):908
8. WIlliams JW Jr, Aguilar C, Makela M, et al. 1999. Cochrane Library. 26 May 1999
9. Super M. 2000. Lancet. 355(9218):1840
10. Wang XJ, Moylan B, Leopold DA, et al. 2000. JAMA. 284(14):1814
11. Brown RB and Lau SK. 2001. NEJM. 344(4):286 (Case Record)
12. Snow V, Mottur-Pilson C, Hickner JM. 2001. Ann Intern Med. 134(6):495
13. Hickner JM, Bartlett JG, Besser RE, et al. 2001. Ann Intern Med. 134(6):498
14. Dolor RJ, Witsell DL, Hellkamp AS, et al. 2001. JAMA. 286(24):3097
15. Bhattacharyya N and Fried MP. 2003. Laryngoscope. 113:125
16. Azithromycin Extended Release. 2005. Med Let. 47(1218):78
17. Cunningham MJ, Lin DT, Curry WT Jr., et al. 2007. NEJM. 356(26):2721 (Case Record)