What every physician needs to know.

Sinusitis affects 1 in 7 adults (31 million people) in United States each year with an estimated healthcare cost of almost $6 million. More than 20% of adult antibiotic prescriptions are for sinusitis, making it the fifth most common diagnosis for which antibiotics are prescribed. The goals of diagnosing and managing sinusitis focuses on reducing inappropriate use of antibiotics and radiographic imaging.

“Sinusitis” is defined as inflammation of one or more of the paranasal sinuses; because sinusitis rarely occurs without inflammation of contiguous nasal mucosa, “rhinosinusitis” is the preferred term. Most cases of rhinosinusitis involve more than one of the paranasal sinuses, most commonly the maxillary and ethmoid sinuses. Isolated infection of a frontal or sphenoid sinus is a rare and potentially dangerous condition.

“Rhinosinusitis” is defined as symptomatic inflammation of the nasal cavity and paranasal sinuses, characterized by two or more of the following symptoms: blockage/congestion, discharge (anterior or postnasal drip), facial pain/pressure, reduction or loss of smell. Most cases of rhinosinusitis involve more than one of the paranasal sinuses, typically the maxillary and ethmoid sinuses. Isolated infection of a frontal or sphenoid sinus is a rare and potentially dangerous condition, usually caused by bacteria.

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Anatomical abnormalities frequently present with obstruction, with rhinorrhea as a less prominent symptom. Septal deviation can cause unilateral or bilateral congestion and recurrent sinusitis. Diagnosis may require rhinopharyngoscopy.

Granulomatosis with polyangiitis (formerly known as Wegener granulomatosis) may present with nasal and sinus complaints of purulent rhinorrhea, septal perforations, and septal erosions. Nasal inflammation can cause cartilage damage and collapse resulting in a saddle nose deformity.

II. Diagnostic Confirmation: Are you sure your patient has sinusitis?

The cardinal symptoms of acute rhinosinusitis are purulent nasal drainage accompanied by nasal obstruction and/or facial pain-pressure-fullness. These symptoms have been identified as the most highly predictive symptoms of acute rhinosinusitis whether bacterial or viral.

It is important to distinguish presumed acute bacterial rhinosinusitis from rhinosinusitis caused by viral upper respiratory infections (URI) or noninfectious conditions. Bacterial rhinosinusitis should be diagnosed when signs and symptoms of acute rhinitis persist longer than ten days, or signs and symptoms of rhinitis worsen after initial improvement (double worsening).

A. History Part I: Pattern Recognition:


For purposes of diagnosis and treatment, rhinosinusitis is classified as:

  • Acute rhinosinusitis (ARS) – symptom duration less than 4 weeks. ARS is further classified as acute bacterial rhinosinusitis (ABRS) or acute viral rhinosinusitis (AVRS).
  • Subacute rhinosinusitis – symptoms duration of 4-12 weeks.
  • Chronic rhinosinusitis (CRS) – symptom duration of greater than 12 weeks. Symptoms of CRS vary in severity and prevalence. Nasal obstruction is the most common symptom, followed by facial congestion-pressure-fullness, discolored nasal discharge, and hyposmia. The presence of two or more signs/symptoms persisting beyond 12 weeks is highly sensitive for diagnosing CRS. Facial pain/pressure must be accompanied by other nasal signs and symptoms.
  • Recurrent acute rhinosinusitis – 4 or more episodes of ARS per year lasting at least seven days, with interim symptom free periods. Diagnosis of recurrent ARS requires that each episode meet the criteria for ABRS. Confirming diagnosis of each true bacterial episode is difficult but desirable.
  • Uncomplicated rhinosinusitis – rhinosinusitis without clinically evident extension of inflammation outside the paranasal sinuses and nasal cavity at the time of diagnosis (e.g., no neurologic, ophthalmologic or soft tissue involvement).

The symptom burden is similar in both recurrent rhinosinusitis and CRS, however, antibiotic utilization is higher in the former. Patients with both conditions may benefit from nasal culture or imaging studies. Risk factors for both recurrent and chronic rhinosinusitis include allergic rhinitis, cystic fibrosis, immunocompromised state, ciliary dyskinesia, and anatomic variation. The most common primary immunodeficiency disorders associated with CRS and recurrent ARS are IgA deficiency, common variable immunodeficiency and hypogammaglobulinemia.

B. History Part 2: Prevalence:

The most common etiology of ARS is a viral upper respiratory infection. Viral rhinosinusitis is complicated by acute bacterial infection in only 0.5 to 2%. The following are additional factors associated with sinusitis:

Common causes

  • Viral infection, especially upper respiratory infections
  • Allergic rhinitis
  • Turbinate edema in setting of pregnancy
  • Anatomical variations

    Abnormality of the osteomeatal complex (see Figure 1

    Septal deviation

    Concha bullosa

    Hypertrophic middle turbinates

  • Cigarette smoking
  • Diabetes mellitus
  • Swimming, diving, high altitude climbing
  • Dental infections and procedures
  • Gastroesophageal reflux disease
  • Medication/drug effect (i.e., cocaine, topical vasoconstrictors)
Fig 1
Anatomy of the osteomeatal complex

Rarer causes

  • Cystic fibrosis
  • Neoplasia
  • Mechanical ventilation
  • Use of nasal tubes, such as nasogastric feeding tubes
  • Aspirin Exacerbated Respiratory Disease (AERD) also known as Samter’s triad (aspirin sensitivity, rhinitis, asthma)
  • Sarcoidosis
  • Granulomatosis with polyangiitis
  • Immune deficiency
  • Sinus surgery
  • Immotile cilia syndrome
  • Intranasal cocaine

Rhinosinusitis from allergy and irritants are more likely to be chronic and/or recurrent. Infectious causes of rhinosinusitis include viruses, bacteria, and fungi. Most common viruses determined by maxillary sinus puncture are rhinovirus, influenza virus, and parainfluenza virus.

Community acquired acute bacterial rhinosinusitis is most commonly caused by Streptococcus pneumoniae and Haemophilus influenzae. Bacteria are most commonly isolated from the maxillary sinuses. If ABRS occurs as a result of dental root infection into the sinus cavity, microaerophilic and anaerobic bacteria may be identified.

Nosocomial bacterial rhinosinusitis is an acute sinusitis that can affect patients in intensive care units (ICUs), typically presenting as fever of unknown origin. Patients with extended stay in an ICU and those with prolonged intubation, particularly nasotracheal intubation, are at increased risk of developing ABRS. The most common pathogens associated with nosocomial-bacterial rhinosinusitis are gram negative bacteria including Pseudomonas aeruginosa, klebsiellae pneumoniae, enterobacter species, proteus mirabilis, serratia marcescens and S.aureus.

C. History Part 3: Competing diagnoses that can mimic sinusitis

A. Nasal polyps

B. Structural/mechanical factors

  • Deviated septum/septal wall anomalies
  • Adenoidal hypertrophy
  • Trauma
  • Foreign bodies
  • Nasal Tumors – benign, malignant
  • Choanal atresia
  • Cleft palate
  • Pharyngonasal reflux

C. Cerebrospinal fluid rhinorrhea

D. Ciliary dyskinesia syndrome

Nasal polyps are benign growths which can cause unilateral or bilateral nasal obstruction, loss of smell and/or rhinorrhea. Anatomic abnormalities usually present with prominent obstructive symptoms and less severe rhinorrhea. Septal deviation can cause symptoms of unilateral or bilateral congestion, or recurrent sinusitis. Diagnosis might require fibreoptic rhinopharyngoscopy or computed tomography (CT) scanning.

Nasal tumors can be benign or malignant and most commonly present with obstruction.

D. Physical Examination Findings

Initial diagnostic evaluation should include vital signs and physical examination of the head and neck. Notable findings include diffuse edema and erythema localized over the involved cheekbone or periorbital area; palpable cheek tenderness or tenderness/percussion of the upper teeth; nasal or purulent drainage in the posterior pharynx; signs of extra-sinus involvement (orbital or facial cellulitis (See Figure 2), orbital protrusion, abnormal eye movements, neck stiffness).

Fig 2
Orbital cellulitis

Anterior rhinoscopy may reveal diffuse mucosal edema narrowing of the middle turbinate, inferior turbinate hypertrophy, copious rhinorrhea or purulent discharge.

Polyps or septal deviation may be noted.

Transillumination has limited value as a diagnostic technique (see Figure 3).

Fig 3
Transillumination of the Maxillary Sinus.

A light source is placed along the infraorbital rim. and the hard palate is inspected.

E. What diagnostic tests should be performed?


Endoscopic or sinus aspirate cultures, can be performed by otholaryngologists using rigid optical scopes. While it is not indicated in routine medical practice, it should be considered if:

  • There is suspicion for intracranial extension of the sinus infection.
  • Atypical pathogens are suspected, including patients with nosocomial sinusitis.
  • Patient who are immunocompromised, with cystic fibrosis or recent hospitalization.
  • Patients who are not responding to empiric antibiotics.

Microbiologic tests including viral cultures of nasal secretions are unnecessary as viral rhinosinusitis is self-limited and bacterial cultures drawn from blind nasal swabs are not reliable.

Chronic rhinosinusitis and recurrent acute rhinosinusitis

Diagnostic testing used to investigate underlying causes of CRS and recurrent acute rhinosinusitis include nasal endoscopy, radiographic imaging (see Figure 4) and allergy and immune testing.

Fig 4
Plain Radiograph of the Sinuses.

The right maxillary sinus shows mucosal thickening (arrow).

Nasal endoscopy evaluates inflammatory mucosal disease, obstructions, masses and obtains middle meatal cultures. In recurrent ARS nasal endoscopy confirms purulent nasal discharge for diagnosis, evaluate obstructions and obtain middle meatal cultures.

Radiographic imaging evaluates inflammatory disease and anatomic obstruction in CRS and can be used to evaluate anatomical obstruction in recurrent acute rhinosinusitis.

Allergy and immune testing can be used to detect allergies and immunodeficient states in both the disease conditions. An immunodeficient state should be suspected in patients with CRS or recurrent ARS, especially when rhinosinusitis is associated with otitis media, bronchitis, bronchiectasis, or pneumonia.

If patients have persistent purulent infections immune testing should be recommended and includes quantitative measurement of IgG, IgA, IgM levels and assessment of antibody response to protein and polysaccharide antigens such as tetanus toxoid or pneumococcal polysaccaride vaccine. T-cell number and function can be measured to evaluate cell mediated immunity.

2. What imaging studies (if any) should be ordered to help establish the diagnosis? How should the results be interpreted?

Radiography is not routinely recommended for initial evaluation of uncomplicated sinusitis. It is helpful when a complication of ARS or alternative diagnoses, such as malignancy or other noninfectious causes of facial pain, are suspected.

Sinus CT is preferable to plain films as it allows for better visualization of boney and soft tissue detail. In addition, plain sinus radiography has poor sensitivity and specificity to detect mucosal thickening of the paranasal sinuses and is associated with both high false negative and false positive rates.

Non-contrast sinus CT is the imaging modality of choice to evaluate the paranasal sinuses. Common CT findings in sinusitis include mucosal thickening, air-fluid levels and air bubbles within the sinuses.

Iodine contrast-enhanced CT is indicated in patients with signs and symptoms of complicated sinusitis including diminished visual acuity diplopia, peri-orbital edema, severe headache, or altered mental status, and is helpful in recurrent or treatment-resistant rhinosinusitis to detect blockage of osteo-meatal complex.

Magnetic resonance imaging (MRI) is useful in ARS in conjunction with CT when extra-sinus involvement is suspected.

III. Default Management.

Symptomatic treatment and reassurance is the preferred management strategy for patients with mild rhinosinusitis. Antibiotics are reserved for patients who present with moderate to severe symptoms lasting longer than 7 days that meet diagnostic criteria for clinical diagnosis of acute bacterial rhinosinusitis. Antibiotics are also indicated for treatment of severe rhinosinusitis regardless of duration of illness.

It is clinically difficult to distinguish between AVRS and ABRS during the first ten days of illness. AVRS is a self-limited disease. Treatment, in general, should be symptomatic and supportive. Analgesics such as NSAIDS and acetaminophen are recommended for pain relief. Intranasal saline irrigation is recommended for AVRS and as adjunctive treatment for ABRS.

Neither topical or systemic decongestants are recommended as adjunctive treatment in ABRS. Nasal steroids can also be used to decrease nasal inflammation and is especially recommended in patients who also suffer from allergic rhinitis. Commonly used nasal steroids include beclomethasone AQ or metered-dose inhaler MDI, budesonide MDI, flunisolide, fluticasone, triamcinolone AQ or MDI, and dexamethasone MDI.

Systemic review of four randomized placebo-controlled trials have shown significantly greater improvement or resolution of symptoms with intransal steroids as monotherapy for mild sinusitis than placebo alone. A randomized trial of mometasone furoate 200 mcg twice daily was superior to placebo and oral amoxicillin.

Topical decongestants like oxymetazoline have been shown to significantly reduce edema, but should not be used more than three days to avoid rebound congestion. Topical decongestants offer fewer systemic side effects compared to their oral counterparts.

Oral decongestants are frequently used to reduce mucosal edema and facilitate aeration and drainage. Evidence has shown that among several oral decongestants only oral ephedrine sulfate was superior to placebo. Rhinorrhoea can occur from excessive parasympathetic stimulation of the submucous gland of the paranasal mucosa. Ipratropium bromide 0.06% has been shown to significantly diminish such rhinorrhea. Mucolytics such as guaifenesin serve to thin secretions and may promote ease of mucous drainage and clearance.

As soon as ABRS is suspected, antibiotic therapy should be initiated. Antibiotic selection is made based on the narrowest spectrum that includes most common pathogens with the rationale to minimize drug resistance. In theory, culture-directed therapy is optimal but in ABRS, cultures are obtained through either endoscopy or antral puncture and are reserved for patients with complicated sinusitis.

The Infectious Disease Society of American recommends amoxicillin-clavulanate as initial empiric antimicrobial therapy for ABRS with low risk for resistance. In the case of penicillin allergy, a respiratory fluoroquinolone (levofloxacin, moxifloxacin) or doxycycline should be used. In areas with high-endemic rates of penicillin-resistant organisms, or in patient meeting any of the following criteria: daycare attendance, age <2 years or >65 years, recent hospitalization, antibiotic use in the last month or immunocompromised, high-dose amoxicillin-calvulanate should be used as empiric treatment.

Trimethoprim-sulfamethoxazole and macrolides (azithromycin, clarithromycin) are not recommended for empiric therapy due to high rates of resistance of S. pneumonia and Haemophilus influenza.

If symptom improvement is seen within 3-5 days of starting antibiotic therapy, continue therapy for a total of 5-7 days. If symptoms worsen after 48-72 hours of therapy, or fail to improve within 3-5 days of treatment, broaden coverage or switch to a different antibiotic class. If symptoms improve with initiation of second-line antibiotic, treat for 5-7 days of therapy; if symptoms continue to worsen or do not improve after 3-5 days, consider a CT scan or MRI to evaluate for non-infectious causes or suppurative complications (i.e. orbital or intracranial extension of infection). Also consider sinus or meatal cultures.

A. Immediate management.

Serious complications of acute bacterial rhinosinusitis such as meningitis, brain abscess, periorbital cellulitis (see Figure 2), and cavernous sinus thrombosis occur due to extension of sinus infection into the central nervous system. In these patients, surgery may be emergently indicated.

Similarly, acute fulminant invasive fungal sinusitis (IFRS) is a disease of immunosuppressed patients or patients with poorly controlled diabetes. As it can be rapidly progressive and life-threatening, immediate diagnosis and emergency otolaryngologist consultation is required.

B. Physical Examination Tips to Guide Management.

Treatment failure is defined as lack of improvement in symptoms 3-5 days after starting first-line therapy or worsening of symptoms 48-72 hours after treatment initiation. Patients who fail first-line antibiotic therapy may need alternative antibiotics (see above).

Relapse after initial treatment – symptoms recurring within two weeks of response to initial treatment usually represents inadequate eradication of the infection. Generally, for mild relapse of symptoms, a longer course of the same antibiotic is used. If the relapse symptoms are moderate to severe, a change in antibiotic is required as this could be a result of antibiotic-resistant organisms.

Physical signs suggestive of extra-sinus complications of bacterial sinusitis including periorbital and orbital abscess, epidural abscess, meningitis and brain abscess need immediate attention as they require aggressive management and surgery.

C. Laboratory Tests to Monitor Response To, and Adjustments in, Management.

As mentioned above, if patients with acute bacterial sinusitis fail to respond after 3-5 days of second-line antibiotic therapy, endoscopy is required to obtain bacterial culture for culture-directed antibiotic therapy. Also, a CT scan of the paranasal sinuses (see Figure 5) may be performed if symptoms continue to worsen, or if they fail to improve with initial therapy, as it may help to differentiate from other diagnoses like polyps and structural abnormalities.

Fig 5
CT Scans of the Paranasal Sinuses.

Panel A shows normal sinuses. In panel B, the air–fluid level in the left maxillary sinus (arrow) suggests the presence of acute sinusitis.

E. Common Pitfalls and Side-Effects of Management

Sinusitis is one of the most common diseases in which antibiotics are over used as it can be difficult to distinguish viral sinusitis from bacterial sinusitis.

IV. Management with Co-Morbidities


G. Immunosuppression (HIV, chronic steroids, etc).

Sinusitis is a recurrent or chronic problem in 30-68% of patients with HIV infection.

VI. Patient Safety and Quality Measures

B. Appropriate Prophylaxis and Other Measures to Prevent Readmission.

Primary prevention

Patients with CRS and recurrent ARS cannot prevent disease onset, but can engage in practices that may reduce the risk of developing VRS, which often precedes ABRS. Patients can minimize their exposure to pathogens by practicing good hand hygiene, especially when in contact with ill-individuals. Washing hands with soap or using an alcohol-based hand rub is one of the most effective strategies for reducing the risk of developing VRS.

Secondary prevention

Secondary prevention minimizes symptoms and exacerbation of CRS and recurrent ARS when symptoms are initially detected. Saline nasal irrigation is recommended for secondary prevention and after sinus surgery. A systematic review of the evidence linking GERD and sinusitis reveals weak evidence but a pilot study demonstrated that the treatment of GERD with a proton pump inhibitors may prevent CRS.

Since CRS and recurrent acute rhinosinusitis have periods of symptom exacerbation, clinicians and patients should work together in developing treatment strategies that can minimize symptoms, promote recovery and prevent recurrences.