AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Background

Sinusitis refers to inflammation of the lining of the paranasal sinuses. Because the nasal mucosa is simultaneously involved and because sinusitis rarely occurs without concurrent rhinitis, rhinosinusitis is now the preferred term for this condition (Lanza, 1997). By definition, symptoms of acute rhinosinusitis last less than 3 weeks, symptoms of subacute rhinosinusitis last 21-60 days, and symptoms of chronic rhinosinusitis last more than 60 days. The Agency for Healthcare Research and Quality accepted this terminology in 1999.

Rhinosinusitis may be further classified according to the anatomic site (maxillary, ethmoidal, frontal, sphenoidal), pathogenic organism (viral, bacterial, fungal), presence of complication (orbital, intracranial), and associated factors (nasal polyposis, immunosuppression, anatomic variants).

Pathophysiology

The vast majority of rhinosinusitis episodes are caused by viruses. Most viral upper respiratory infections are caused by rhinovirus, but coronavirus, influenza A and B, parainfluenza, respiratory syncytial virus, adenovirus, and enterovirus are also causative agents.

Almost 90% of patients with upper respiratory infections have radiographic evidence of paranasal sinus involvement. However, only 0.5-2% of viral rhinosinusitis infections are complicated by bacterial infection (Gwaltney, 1996).

The pathophysiology of rhinosinusitis is related to 3 factors: obstruction of sinus drainage pathways (sinus ostia), ciliary impairment, and mucus quantity and quality.

• Obstruction of the natural sinus ostia prevents normal mucus drainage. Edema, inflammation, polyps, tumors, trauma, scarring, anatomic variants (eg, concha bullosa [pneumatized middle turbinate], septal deviation), and nasal instrumentation (nasogastric tubes or packing) can result in decreased patency of sinus ostia. Hypoxia within the obstructed sinus is thought to cause ciliary dysfunction and alterations in mucus production, further impairing the normal mechanism for mucus clearance.
• Contrary to earlier models of sinus physiology, the drainage patterns of the paranasal sinuses depend not on gravity but on the mucociliary transport mechanism. The metachronous coordination of the ciliated columnar epithelial cells propels the sinus contents toward the natural sinus ostia. Any disruption of the ciliary function results in fluid accumulation within the sinus. Poor ciliary function can result from the loss of ciliated epithelial cells; cold air; high airflow; viral, bacterial, or environmental ciliotoxins; inflammatory mediators; contact between 2 mucosal surfaces; scars; and primary ciliary dyskinesia (Kartagener Syndrome).
• Sinonasal secretions play an important role in the pathophysiology of rhinosinusitis. The mucus that lines the paranasal sinuses is composed of a thin periciliary layer, which enables ciliary mobility, and a thick gel layer, which anchors the tips of the cilia. This mucous blanket contains mucoglycoproteins, immunoglobulins, and inflammatory cells. Alterations in the water content of the mucous blanket can impair ciliary mobility. Overproduction of mucus can overwhelm the mucociliary clearance system, resulting in retained secretions within the sinuses.
• Acute bacterial rhinosinusitis is very frequently associated with viral upper respiratory infection, although allergy, trauma, neoplasms, midline destructive disease, environmental factors, dental infection, and anatomic variation, which may impair normal mucociliary clearance, are also thought to be factors that predispose to bacterial infection.

Frequency

United States

Rhinosinusitis affects 35 million people per year in the United States and accounts for close to 16 million office visits per year (Lucas, 2004). According to the National Ambulatory Medical Care Survey (NAMCS), approximately 14% of adults report having an episode of rhinosinusitis each year, and it is the fifth most common diagnosis for which antibiotics are prescribed. In 1996, Americans spent approximately $3.39 billion treating rhinosinusitis (Ray, 1999).

Approximately 0.5-2% of cases of viral rhinosinusitis are complicated by bacterial superinfection.

Sinusitis is more common from early fall to early spring.

Mortality/Morbidity

Forty percent of acute rhinosinusitis cases resolve spontaneously. Untreated or inadequately treated rhinosinusitis may lead to complications such as meningitis, cavernous sinus thrombophlebitis, orbital cellulitis or abscess, and brain abscess.

Race

No racial predilection exists.

Sex

No sex predilection exists.

Age

Sinusitis occurs in all age groups.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

History

Ask about a preexisting history of allergic or occupational rhinitis, vasomotor rhinitis, nasal polyps, rhinitis medicamentosa, or an immunodeficiency. Rhinosinusitis is more common in patients with congenital defects that affect humoral immunity and ciliary motility, in those with cystic fibrosis, and in patients with AIDS. Obtain a history of diabetes or organ transplant if invasive fungal sinusitis is being considered.

Overdiagnosis of acute bacterial rhinosinusitis is common. Acute bacterial rhinosinusitis is the correct diagnosis in 40-50% of cases in which a primary care physician initially classifies a patient as likely having the condition (Hansen, 1995).

The natural history of rhinovirus infection, as described by Gwaltney et al, lasts from 1-33 days. One fourth of patients have symptoms that last longer than 14 days (Gwaltney, 1967).

• Patients with uncomplicated upper respiratory infections usually report some of the following symptoms: sneezing, rhinorrhea, nasal congestion, hyposmia/anosmia, facial pressure, postnasal drip, sore throat, cough, ear fullness, fever, and myalgia.
• Although diagnostic criteria for acute rhinosinusitis have been proposed (Lanza, 1997), no single sign or symptom has strong diagnostic value for bacterial rhinosinusitis (Hickner, 2001). However, acute bacterial rhinosinusitis should be suspected in patients who exhibit symptoms of a viral upper respiratory infection that do not improve after 10 days or worsen after 5-7 days.
• Symptoms of acute bacterial rhinosinusitis include the following:
• • Facial pain or pressure (especially unilateral)
  • Hyposmia/anosmia
  • Nasal congestion
  • Nasal drainage
  • Postnasal drip
  • Fever
  • Cough
  • Fatigue
  • Maxillary dental pain
  • Ear fullness/pressure
• A change in the color or characteristic of the nasal discharge is not a specific sign of bacterial rhinosinusitis.
• A previous diagnosis of rhinosinusitis is not a predictor of acute bacterial rhinosinusitis (Hickner, 2001).

Physical

• Purulent nasal secretions
• Purulent posterior pharyngeal secretions
• Mucosal erythema
• Periorbital edema
• Tenderness overlying sinuses
• Air-fluid levels on transillumination of the sinuses (60% reproducibility rate for assessing maxillary sinus disease)
• Facial erythema

Causes

The most common pathogens isolated from maxillary sinus cultures in patients with acute bacterial rhinosinusitis include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Streptococcus pyogenes, Staphylococcus aureus, and anaerobes are less commonly associated with acute bacterial rhinosinusitis.

• S pneumoniae are gram positive, catalase-negative, facultatively anaerobic cocci that account for 20-43% of acute bacterial rhinosinusitis in adults. The rise of antimicrobial resistance in S pneumoniae is a major concern. A 1998 surveillance study of respiratory tract isolates estimated that 12.3% of S pneumoniae isolates obtained from the paranasal sinuses had intermediate resistance to penicillin; 37.4% were penicillin-resistant. The paranasal sinuses represented the anatomic location with the highest resistance rate (Jacobs, 2004). Resistance to macrolide, clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), and doxycycline was more common in isolates with intermediate penicillin resistance and those that were penicillin-resistant.
• H influenzae are gram-negative, facultatively anaerobic bacilli. H influenza type B was a leading cause of meningitis until the widespread use of the vaccine. Nontypeable strains of H influenza are responsible for 22-35% of acute bacterial rhinosinusitis cases in adults. M catarrhalis are gram-negative, oxidase-positive, aerobic diplococci. M catarrhalis is the responsible pathogen in 2-10% of acute bacterial rhinosinusitis cases in adults. Beta-lactamase production is the mechanism of antimicrobial resistance for both M catarrhalis and H influenza. Of isolates from the paranasal sinus, 32.7% and 98% were found to be beta-lactamase–positive for H influenza and M catarrhalis, respectively.
• Rarely, sinusitis may be caused by fungi, including Mucorales genera and Aspergillus or Candida species. Fungal infections are more common in people with diabetes and those who are immunocompromised. Clinicians should maintain a high index of suspicion for acute invasive fungal sinusitis in immunocompromised patients with orbital or CNS complications of rhinosinusitis.

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Other Problems to be Considered

Gastroesophageal reflux
Cystic fibrosis
Immotile cilia syndrome
Migraine headache
Sinonasal polyposis
Chemical rhinitis
Nasal foreign body
Chronic invasive fungal sinusitis
Sinonasal neoplasm

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Lab Studies

• The erythrocyte sedimentation rate and C-reactive protein level may be elevated, but these findings are nonspecific.
• The findings of CBC count with differential may be within reference ranges.
• Nasal cytology examinations may be useful to elucidate the following entities:
• • Allergic rhinitis
  • Eosinophilia
  • Nasal polyposis
  • Aspirin sensitivity
• Sweat chloride test screening should be performed if cystic fibrosis is suggested.
• Ciliary function studies help screen for Kartagener syndrome.
• Tests for immunodeficiency are indicated if history findings indicate recurrent infection, to include the following:
• • Immunoglobulin levels
  • HIV serology
• Cultures of nasal secretions are of limited value because they are usually contaminated by normal flora.

Imaging Studies

• Findings on standard radiographs are insensitive, especially for ethmoidal disease. Waters view is best.
• CT scanning is the preferred imaging method.
• • A screening sinus CT scan is adequate for diagnosis and less expensive than other methods but is necessary only in cases of treatment failure or chronic disease.
  • A complete sinus CT scan with frontal and coronal planes is used if an alternate diagnosis (eg, tumors) must be excluded.
  • CT scan findings are used to differentiate orbital cellulitis from periorbital cellulitis as a complication or to evaluate extension into intracranial space.
• MRI is useful only if fungal infection or a tumor is suggested.
• Ultrasound is of limited use.

Procedures

• A paranasal biopsy is used to help exclude neoplasia, fungal disease, and granulomatous disease.
• Fiberoptic sinus endoscopy is used to visualize posterior sinonasal structures. This test is useful in chronic or recurrent disease and to help exclude structural lesions, fungal disease, and granulomatous diseases.

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical Care

Improved mucociliary function and control of infection are the goals of therapy.

Surgical Care

Antral puncture and irrigation are used for diagnostic culture and sensitivity testing in immunosuppressed or critically ill patients if the organism must be identified. However, more recent data support the role of endoscopically guided middle meatus cultures instead.

Consultations

• Ear, nose, and throat specialist for complications or when routine management techniques fail
• Infectious disease specialist in complicated cases

MEDICATION

Section 7 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Viral rhinosinusitis does not require antimicrobial treatment.

Standard nonantimicrobial treatment options include topical steroids, topical and/or oral decongestants, mucolytics, and intranasal saline spray. However, intranasal steroid spray is the only medication whose use is supported by placebo-controlled trials. Topical steroids have been shown to reduce time to symptom resolution in cases of acute rhinosinusitis treated both with and without antibiotics (Meltzer, 2005).

No data are available to suggest that antihistamines are beneficial in acute sinusitis. In fact, antihistamines may cause harm by drying mucous membranes and decreasing clearance of secretions.

Drug Category: Antibiotics

Bacterial efficacy rates are as follows:

• Levofloxacin, moxifloxacin, and amoxicillin/clavulanate - Greater than 90%
• High-dose amoxicillin, cefpodoxime proxetil, cefixime, cefuroxime axetil and trimethoprim-sulfamethoxazole - 80-90%
• Clindamycin, doxycycline, cefprozil, azithromycin, clarithromycin, and erythromycin - 70-80%
• Cefaclor and loracarbef - 50-60%

Based on the 2000 Sinus and Allergy Health Partnership treatment guidelines for acute bacterial rhinosinusitis, patients are divided into 3 groups, as follows:

• Adults with mild disease who have not received antibiotics: Amoxicillin/clavulanate, amoxicillin (1.5-3.5 g/d), cefpodoxime proxetil, or cefuroxime is recommended as initial therapy.
• Adults with mild disease who have had antibiotics in the previous 4-6 weeks and adults with moderate disease: Amoxicillin/clavulanate, amoxicillin (3-3.5 g), cefpodoxime proxetil, or cefixime is recommended.
• Adults with moderate disease who have received antibiotics in the previous 4-6 weeks: Amoxicillin/clavulanate, levofloxacin, moxifloxacin, or amoxicillin or clindamycin plus cefpodoxime proxetil or cefixime is recommended.

Patients who remain symptomatic despite appropriate antibiotic therapy may be evaluated with sinus endoscopy, CT scan, or sinus aspiration/culture.

Drug Category: Topical decongestants

-- These agents cause vasoconstriction, which reduces nasal congestion.

Drug Category: Corticosteroids: Topical decongestants

-- These agents are beneficial, especially if underlying rhinitis is present.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Further Outpatient Care

• Symptomatic or adjunctive therapies may include the following:
• • Humidification/vaporizer
  • Warm compresses
  • Adequate hydration
  • Smoking cessation
  • Balanced nutrition
  • Nonnarcotic analgesia
• Antihistamines are not recommended and have not proven beneficial:

Complications

• Treatment fails in 10-25% of patients. If this occurs, consider the following:
• • Take a repeat history and perform an additional physical examination; consider an imaging study.
  • Start second-line antibiotics.
• Approximately 75% of orbital or periorbital infections are the result of extending sinusitis.
• Untreated, inadequately treated, or partially treated rhinosinusitis may lead to chronic rhinosinusitis, meningitis, brain abscess, or other extra-sinus complications.

Prognosis

• Approximately 40% of acute sinusitis cases resolve spontaneously without antibiotics.
• The relapse rate after successful treatment is less than 5%.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical/Legal Pitfalls

• Failure to recognize and aggressively evaluate and treat in light of the following concurrent diagnoses:
• • HIV/AIDS
  • Diabetes
  • Hematologic malignancy
  • Immunocompromise
• Failure to recognize complications

ACKNOWLEDGMENTS

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous coauthor Michael Cunningham, DO, to the development and writing of this article.

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

• Bailey BJ, Calhoun KH, et al. Head & Neck Surgery - Otolaryngology, 3rd edition. 2001;vol 1.
• Benninger MS, Payne SC, Ferguson BJ, et al. Endoscopically directed middle meatal cultures versus maxillary sinus taps in acute bacterial maxillary rhinosinusitis: a meta-analysis. Otolaryngol Head Neck Surg. Jan 2006;134(1):3-9.
• Berkow R, Beers MH, eds. Sinusitis. In: The Merck Manual of Diagnosis and Therapy. 16th ed. Whitehouse Station, NJ: Merck & Company; 1992. [Full Text].
• Fagnan LJ. Acute sinusitis: A Cost-Effective Approach to Diagnosis and Treatment. In: American Family Physician. Leawood, Kans: American Academy of Family Physicians; 1998. [Full Text].
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• Hansen JG, Schmidt H, Rosborg J, Lund E. Predicting acute maxillary sinusitis in a general practice population. BMJ. Jul 22 1995;311(6999):233-6. [Medline].
• Hickner JM, Bartlett JG, Besser RE. Principles of appropriate antibiotic use for acute rhinosinusitis in adults: background. Ann Intern Med. Mar 20 2001;134(6):498-505. [Medline].
• Jacobs MR, Bajaksouzian S, Windau A. Susceptibility of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis to 17 oral antimicrobial agents based on pharmacodynamic parameters: 1998-2001 U S Surveillance Study. Clin Lab Med. Jun 2004;24(2):503-30.
• Lanza DC, Kennedy DW. Adult rhinosinusitis defined. Otolaryngol Head Neck Surg. Sep 1997;117(3 Pt 2):S1-7. [Medline].
• Lucas JW, Schiller JS, Benson V. Summary health statistics for U.S. adults: National Health Interview Survey, 2001. Vital Health Stat 10. Jan 2004;1-134.
• Meltzer EO, Bachert C, Staudinger H. Treating acute rhinosinusitis: comparing efficacy and safety of mometasone furoate nasal spray, amoxicillin, and placebo. J Allergy Clin Immunol. Dec 2005;116(6):1289-95.
• National Ambulatory Medical Care Survey. Ambulatory Health Care Data. [Full Text].
• Ray NF, Baraniuk JN, Thamer M. Healthcare expenditures for sinusitis in 1996: contributions of asthma, rhinitis, and other airway disorders. J Allergy Clin Immunol. Mar 1999;103(3 Pt 1):408-14. [Medline].
• Sinus and Allergy Health Partnership. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Sinus and Allergy Health Partnership. Otolaryngol Head Neck Surg. Jul 2000;123(1 Pt 2):5-31.
• Skoner DP. Complications of allergic rhinitis. J Allergy Clin Immunol. June 2000;105:605-609. [Medline].
• Williams JW Jr, Aguilar C, Makela M, et al. Antibiotics for acute maxillary sinusitis. Cochrane Database Syst Rev. 2000;(2):CD000243. [Medline].

Article Last Updated: Feb 14, 2007