A 51-Year-Old Woman With Acute Onset of Facial Pressure, Rhinorrhea, and Tooth Pain: Title and subTitle BreakReview of Acute Rhinosinusitis

DR REYNOLDS: Mrs D is a 51-year-old woman with a history of seasonal allergies who presented with 5 days of upper respiratory tract infection symptoms and facial pain.

Mrs D is in good health but has been spending time in a large medical center recently, visiting her husband, who is undergoing chemotherapy. About 5 days before presentation, she noticed the onset of watery eyes, sneezing, chest congestion, nasal mucus production, and myalgias. She thought she had a cold. After a few days she began having pain in her left forehead, under her eye, and near her left upper teeth (she does not have dental problems). She did not have a cough or fever. Her nasal discharge, initially clear, became green. She was concerned about transmitting a sinus infection to her immunocompromised husband. She did not take any over-the-counter medications for her symptoms.

Mrs D has a history of seasonal allergies. She previously saw an allergist who prescribed several years of injections; she then took prescription allergy medication but stopped 2 years ago. She now uses nonprescription loratadine as needed during the allergy season. She typically does not get allergy symptoms during the winter.

Mrs D has had a number of sinus infections diagnosed and treated with antibiotics over the years, the last occurring approximately 2 years ago. She has always been prescribed antibiotics when she has presented with these symptoms in the past.

Mrs D's medical history is significant for hypertension, osteoarthritis, and a partial nephrectomy for a benign tumor. Her medications include atenolol, hydrochlorothiazide, ranitidine, and glucosamine and chondroitin. Mrs D moved to the United States in the 1970s from Haiti. She has 3 grown, healthy children; she does not smoke tobacco, drink alcohol, or use recreational drugs. She has commercial medical insurance.

On physical examination, Mrs D had a blood pressure of 138/78 mm Hg and a temperature of 96.0°F (35.6°C). She looked well and was in no acute distress. Her conjunctivae were clear and without erythema. She had tenderness on palpation over the left frontal and maxillary sinuses but no pain on palpation over her teeth and gums. She had minimal swelling below her left lower eyelid. Her nasal examination showed white rhinorrhea. Her pharynx did not show erythema. Her lungs were clear and her cardiovascular examination results were normal.

About a week ago, I was having a headache, felt very tired, and thought I was coming down with something, but I didn't know what it was. On Sunday I woke up with stuffy nose and watery eyes; headaches again. I felt like I had toothache. And I thought, no, I know it's not a toothache, I don't have anything wrong with my teeth. So I thought it must be a sinus infection that I’m coming down with.

It was hurting on the whole side of my face, and then I could see the puffiness under my eyes. It's like I’m almost deaf in one ear. Talking on the phone, I can hardly hear what the other person is saying. That's how bad it can get.

What was coming out of my nose was clear at first, then after a few days it started to have a greenish color. That's when I thought, definitely, it's a sinus infection, and I need medical attention.

In the past, when I had sinus infections, it usually happened when I was at work. I couldn't concentrate at all, because my head felt like it was going to explode any minute. But lately it's been different symptoms. Basically, you can mistake it for a cold, or you might even think it's allergies because it starts with itchy eyes, itchy throat.

Allergies are usually temporary. I could go to bed with itchy eyes or an itchy throat, and by next morning it's gone, so I know it's allergies. A sinus infection lasts a long time.

I’m used to having sinus infections and I know when I have one. I had one 2 years ago. So on my way to the doctor, I knew I was going to ask for antibiotics, because there's no way I can treat this without having medication. With that type of sinus infection, I don't think [pseudoephedrine hydrochloride] or anything over the counter would have helped me. That's my own opinion, my situation.

I would like to know what the difference is between a common cold and a sinus infection. Where does a sinus infection come from? How do you get it? What triggers it?

How can a physician diagnose acute rhinosinusitis based on patient history and physical examination? What is the microbiology of acute sinusitis? What are the indications, if any, for imaging or endoscopy in patients with symptoms of acute sinusitis? How effective are antibiotics in the treatment of acute rhinosinusitis and what regimens, if any, do you recommend for first-line treatment? What nonpharmacological treatments are effective? What complications of acute rhinosinusitis should primary care physicians look for? What do you recommend for Mrs D?

DR HWANG: Acute rhinosinusitis is defined as symptomatic inflammation of the mucosa of the nasal cavity and paranasal sinuses lasting less than 4 weeks in duration. Because the inflammatory condition almost always extends beyond the sinus cavities to involve the nasal cavity as well,^{1 - 2} the term rhinosinusitis is preferred to sinusitis.

Each year, more than 20 million US adults are diagnosed as having acute bacterial rhinosinusitis.³ The diagnosis and treatment of rhinosinusitis account for an estimated $5.8 billion per year in direct medical expenditures, $3 billion of which is spent on acute bacterial rhinosinusitis.^{3 - 4} The socioeconomic impact of rhinosinusitis is even greater when considering indirect costs from decreased work productivity and missed work days, in addition to global impairment of quality of life.

The paranasal sinuses—maxillary, ethmoid, sphenoid, and frontal—are 4 paired air-filled spaces located between the orbits and below the anterior cranial fossa. They are lined with ciliated, secretory respiratory mucosa. Quiz Ref IDThe sinuses drain through narrow ostia several millimeters in diameter and are prone to obstruction when the mucosal lining swells in response to viral infection or environmental irritation (Figure 1).

The diagnosis of acute rhinosinusitis is based primarily on medical history and is supported secondarily by confirmatory physical findings. In 2007, an updated clinical practice guideline was developed by a multidisciplinary expert panel based on evidence from the literature.⁵ Quiz Ref IDThe guideline proposes that a diagnosis of acute rhinosinusitis should be based on presence of 2 cardinal symptoms: purulent rhinorrhea and either facial pressure or nasal obstruction. Other suggestive signs and symptoms (though not required for the diagnosis) include headache, fever, fatigue, maxillary dental pain, cough, hyposmia or anosmia, and ear pressure or fullness. Although the sensitivity and specificity of this algorithm for the diagnosis of acute sinusitis has not been studied, earlier studies have determined the sensitivity and specificity of the individual cardinal symptoms for a diagnosis of acute sinusitis: purulent rhinorrhea has a sensitivity of 72% and a specificity of 52%; facial pressure has a sensitivity of 52% and a specificity of 48%; and nasal obstruction has a sensitivity of 41% and a specificity of 80%.⁶

Anterior rhinoscopy, performed with a handheld otoscope or fiber-optic nasal endoscope, may reveal diffuse mucosal edema, inferior turbinate hypertrophy, and copious rhinorrhea (Figure 2). Facial tenderness and oropharyngeal discharge may also be supportive of a diagnosis of acute rhinosinusitis. Notably, the aforementioned diagnostic criteria apply to both viral and bacterial rhinosinusitis and do not distinguish between them. The guidelines propose, based on expert consensus, that the duration of acute rhinosinusitis is expected to be less than 4 weeks.¹

The first step in evaluation of Mrs D is determining whether she has acute rhinosinusitis, irrespective of either viral or bacterial etiology. Mrs D describes symptoms of purulent rhinorrhea, facial pressure, and nasal obstruction, satisfying the criteria for cardinal symptoms. She also reports multiple secondary criteria, including headache, fatigue, dental sensitivity, and ear fullness. The duration of her symptoms is less than 4 weeks. Quiz Ref IDAlthough she has a history of nasal allergies, her current symptoms of purulent rhinorrhea and facial pain are not consistent with allergic rhinitis, which would be expected to manifest as clear rhinorrhea, sneezing, and nasal pruritus.⁷ Physical examination findings such as facial tenderness to palpation or tympanic membrane retraction may support a diagnosis of sinusitis but are not required, although in her case, ear examination to assess her reports of ear fullness would be appropriate. Therefore, on the basis of history it is reasonable to diagnose Mrs D as having acute rhinosinusitis.

Determining whether Mrs D has viral vs bacterial rhinosinusitis is a more complex matter. The most common form of acute rhinosinusitis is acute viral rhinosinusitis (AVRS). More than 1 billion viral upper respiratory tract infections are estimated to occur each year in the United States, and an estimated 39% to 87% of upper respiratory tract infections are estimated to result in acute viral rhinosinusitis.^{8 - 9} Acute viral rhinosinusitis, a typically self-limited illness, may be clinically indistinguishable from upper respiratory tract infections without sinusitis. Upper respiratory tract infection is a primary risk factor for the development of acute bacterial rhinosinusitis (ABRS), with approximately 0.5% to 2% of upper respiratory tract infections progressing to bacterial infection.¹⁰ Acute bacterial rhinosinusitis is also largely a self-limited illness, with a 40% to 60% rate of spontaneous resolution, based on systematic review of placebo-controlled clinical trials.⁵ However, antibiotic therapy in patients with ABRS can shorten the duration of symptoms; a meta-analysis of 16 randomized controlled trials in ABRS showed that antibiotics conferred a higher rate of partial or complete resolution of acute rhinosinusitis symptoms compared with placebo, with an odds ratio of 1.64 (95% confidence interval, 1.35-2.00).¹¹ The meta-analysis did not detect a benefit from antibiotics in the prevention of suppurative complications (orbital, intracranial extension), but given the rare incidence of complications, the meta-analysis may have been limited by sample size.

Since viral and bacterial rhinosinusitis can overlap in clinical presentation, it may be difficult to discern viral from bacterial etiologies. In the first 5 days of illness, AVRS and ABRS may be indistinguishable. The diagnostic distinction is thus made based on duration and progression of symptoms.⁵ The expected clinical course of AVRS is marked by resolution of symptoms within 10 days following the onset of an upper respiratory tract infection, whereas ABRS is presumed when acute symptoms persist for 10 days or more. Acute bacterial rhinosinusitis may also be diagnosed if the acute symptom complex exists for less than 10 days but demonstrates clinical worsening after initial improvement.⁵ The presence of “double worsening” carries a likelihood ratio of 2.1 for a diagnosis of ABRS, based on a reference standard of a sinus computed tomography (CT) scan.¹²

Because Mrs D's symptoms have been present for 5 days and the temporal cut point for distinguishing viral from bacterial sinusitis is 10 days, it cannot be determined with certainty whether Mrs D's symptoms represent true bacterial rhinosinusitis.

The most common viruses implicated in AVRS, as determined by maxillary sinus puncture and aspiration in an outpatient setting, are rhinovirus, adenovirus, influenza virus, and parainfluenza virus.^{13 - 14} Owing to a paucity of studies, the relative incidence of each virus in AVRS is not well characterized. The most common pathogens associated with ABRS are Streptococcus pneumoniae (33%), Haemophilus influenzae (32%), Staphylococcus aureus (10%), and Moraxella catarrhalis (9%).¹⁵ In approximately one-quarter of cases, 2 distinct pathogens may be isolated.¹⁶ Since the introduction of the 7-valent pneumococcal vaccine for children, there appears to be a trend toward decreasing S pneumoniae isolates and increasing prevalence of H influenzae isolates derived from adults with acute maxillary sinusitis.¹⁷

In clinical practice, viral culture of nasal secretions is not recommended for routine cases, given the self-limited nature of AVRS. Bacterial culture of purulent secretions may be indicated when there is concern regarding resistant pathogens, such as in cases that are refractory to primary antibiotic therapy, or those involving an immunocompromised host.¹⁸ When cultures are deemed necessary, a referral to an otolaryngologist is appropriate, as culture methods can significantly affect the yield. The gold standard for sinus culture technique is antral puncture and aspiration, which requires a large-bore trocar or needle to be passed through the canine fossa or inferior meatus. Antral puncture may not be practical for routine culture given the morbidity of the procedure, which includes dental or facial pain, bleeding, facial swelling, and false passage of the trocar.^{19 - 20} An excellent alternative to antral puncture is transnasal endoscopic culture, which can be readily performed without significant morbidity in the otolaryngologist's office using a topical anesthetic.²⁰ Endoscopically guided middle meatal cultures have a satisfactory yield and show excellent correlation with antral aspiration.^{20 - 22} In a meta-analysis of 126 patients,²² the yield of endoscopic middle meatal cultures was assessed against the gold standard of maxillary sinus puncture and aspiration performed in the same patient (131 culture pairs). Endoscopic culture had a sensitivity of 80.9%, a specificity of 90.5%, a positive predictive value of 82.6%, a negative predictive value of 89.4%, and an overall accuracy of 87.0%.

At the time of nasal endoscopy, the otolaryngologist can also perform a more detailed examination of the nasal anatomy to identify potential predisposing anatomic factors such as nasal polyps, septal deviation, or nasal masses. Simple blind swabs of the nasal cavity are likely to be contaminated by normal colonizing bacteria of the nasal vestibule and should not be performed.^{23 - 24}

Since Mrs D has had uncomplicated symptoms for only 5 days, there is no role for endoscopic culture in her case. However, if her symptoms persisted for 10 days and she subsequently failed a course of antibiotic therapy, referral for endoscopic sinus cultures would potentially be indicated. In addition, if she were immunocompromised or if an extrasinus complication were suspected, referral to an otolaryngologist would also be indicated.²³

Mrs D did not have any radiographic imaging during this acute episode. Radiographic imaging is generally not indicated in the evaluation of routine uncomplicated acute rhinosinusitis.⁵ If pursued, plain sinus radiography may provide satisfactory images of the maxillary sinus, and it has moderate sensitivity (73%) and specificity (80%) for predicting positive antral puncture results.²⁵ Imaging of the ethmoid, frontal, and sphenoid sinuses offers lower sensitivity and specificity owing to radiologic artifact. Ultrasonography offers uneven diagnostic accuracy because of operator-dependent factors and is therefore not recommended for routine imaging.²⁵ Computed tomography scans offer improved bony and soft tissue detail, but in the context of acute rhinosinusitis, CT scans may reveal sinus fluid levels in patients with AVRS as well as those with ABRS (Figure 3). Since CT scans cannot distinguish between viral and bacterial etiologies, their utility in evaluating acute rhinosinusitis is limited. In a study by Gwaltney et al,⁹ 31 healthy participants who developed AVRS after controlled inoculation demonstrated an 87% mucosal thickening or air-fluid levels of the maxillary sinuses on CT scan. Abnormalities were also documented on CT in the ethmoid, frontal, and sphenoid sinuses in 65%, 32%, and 39%, respectively. After 2 weeks, 79% of the CT abnormalities had cleared. Other studies have shown that radiologic evidence of mucosal abnormality may be observed in as much as 42% of asymptomatic healthy individuals^{26 - 27} ; thus, the significance of a positive CT result must be considered in the appropriate clinical context.

Quiz Ref IDImaging studies are indicated in the evaluation of patients with a suspected complication of ABRS, such as those presenting with diminished visual acuity, diplopia, periorbital edema, severe headache, or altered mental status.⁵ Computed tomography with contrast is the diagnostic study of choice for the evaluation of complicated acute sinusitis that may be extending to the dura, brain, or orbits.^{28 - 29} Magnetic resonance imaging is not indicated for routine evaluation of ABRS but may provide complementary soft tissue detail to CT for the evaluation of complications of acute rhinosinusitis.^{28 - 29}

To minimize the inappropriate use of antibiotics for viral infections, antibiotic treatment should be initiated only when a higher likelihood of ABRS exists.³⁰ The 10th day of symptoms represents the recommended cut point for initiating antibiotic therapy because most cases of AVRS would be expected to resolve within 10 days.⁵ Furthermore, since 40% to 60% of ABRS resolves spontaneously, a significant proportion of patients who have true bacterial sinusitis show evidence of symptom abatement or resolution by day 10 and do not require antibiotics. Quiz Ref IDFor patients with fewer than 10 days of symptoms, observation without antibiotics is therefore recommended if the symptoms are mild and if clinical severity is either stable or improving. Antibiotic treatment is recommended within the first 10 days if patients have severe symptoms or symptoms of “double worsening.” Additional consideration for earlier initiation of antibiotic treatment should be given in immunocompromised hosts.⁵ Mrs D was only 5 days into her course when she was evaluated; because she is an otherwise healthy host, she did not require antibiotic therapy at this stage. She expressed concern over her infection given her husband's immunocompromised state, but since her infection is most likely viral, antibiotics still would not be indicated. She should practice careful hygiene, washing her hands frequently with soap.

For patients with 10 or more days of symptoms, clinicians have the option of initiating antibiotics or continuing with watchful waiting (Table). If a patient has symptoms that are mild or improving and a temperature less than 38.1°C, clinical guidelines support the option of continued observation without antibiotics for an additional 7 days.⁵ The patient may be treated with supportive care for relief of symptoms in lieu of antibiotics. Observation is supported as a viable option by randomized controlled trials (RCTs) of antimicrobials vs placebo; spontaneous improvement of community-acquired, uncomplicated rhinosinusitis may be as high as 73% after 7 to 12 days (vs 87% with antibiotics in the same period).³¹ The watchful waiting option requires a reliable patient who will notify the clinician promptly of any worsening of symptoms, at which point antibiotics should be given. The clinician should also consider factors such as age, immune status, and comorbidities when choosing to observe patients with ABRS.

For patients with 10 or more days of persistent symptoms of rhinosinusitis, antibiotic therapy is equally acceptable as is watchful waiting. Antibiotics are administered to control infection and to secondarily reduce mucosal edema and restore ostial patency.³⁵ The literature regarding the efficacy of antibiotic treatment for acute rhinosinusitis is difficult to interpret because of wide variations in diagnostic inclusion criteria. For example, an RCT by Williamson et al³⁶ concluded that antibiotics (alone or in combination with nasal steroids) showed no benefit vs placebo in the treatment of acute maxillary sinusitis. Participants were older than 15 years of age and met Berg and Carenfelt diagnostic criteria for acute maxillary sinusitis.³⁷ However, patients had a range of 1 to 28 days of symptoms, with a median of 7 days, and based on other studies it is likely that the RCT included significant numbers of patients with viral rhinosinusitis. The subgroup of patients with a longer duration of symptoms may have benefited from antibiotics.

Systematic reviews offer grade B evidence to support the use of antibiotics in ABRS.^{11 ,38 - 43} For mild cases of ABRS, the incremental benefit is somewhat modest. Antibiotics appear to shorten the duration of illness and may increase the rate of cure by 15% (95% confidence interval, 4%-25%) compared with placebo (35% cure for placebo at 7-12 days vs 50% for antibiotics).³¹ The authors calculated that 7 patients would need to be treated to achieve 1 additional positive outcome, while diarrhea and adverse events were 80% more common in those treated with antibiotics. For moderate cases, no RCTs have been published, but treatment of moderate ABRS offers the implied benefit of reducing potential complications.

When antibiotic therapy is initiated, choosing an antimicrobial with the narrowest spectrum against the most probable pathogen is prudent to minimize the risk of cultivating resistance. Amoxicillin (500 mg every 8 hours) is recommended as first-line therapy, given its narrow spectrum, low cost, and favorable adverse effect profile.⁵ Increased rates of penicillin resistance due to penicillin-binding protein–producing S pneumoniae have led to the use of higher dosing regimens of amoxicillin (penicillin-binding proteins can be overcome by the use of amoxicillin instead of penicillin). However, β-lactamase−producing M catarrhalis and H influenzae cannot be overcome by higher dosing and may require combination therapy with clavulanic acid or a change in class of antimicrobial. Resistance rates vary regionally and range from 12% to 31% for intermediate or highly resistant S pneumoniae; 30% to 40% for H influenzae; and ≥90% for M catarrhalis.^{3 ,44 - 45} The increasing incidence of methicillin-resistant S aureus is also of concern (69% incidence among S aureus isolates in data from 2004-2006).⁴⁶ In addition, identification of β-lactamase–negative ampicillin-resistant strains of H influenzae have been reported from Japan and Spain^{47 - 48} ; the mechanism of resistance appears to be a mutation in penicillin-binding proteins.⁴⁹ Locoregional histograms of bacterial resistance should be referenced to understand resistance trends in the local community. Trimethoprim-sulfamethoxazole, macrolides, and second- and third-generation oral cephalosporins have also been validated by RCTs and are cost-effective, acceptable alternative first-line therapies in penicillin-allergic patients.^{3 ,50 - 55}

The recommended duration of antimicrobial therapy based on clinical guidelines is 10 days,⁵ based mostly on the typical duration of therapy used in RCTs.⁵ However, according to a meta-analysis of 12 RCTs,¹¹ no statistical difference in efficacy existed between short-course (3-7 days) vs long-course (6-10 days) treatment (odds ratio, 0.95; 95% confidence interval, 0.81-1.12). Adverse events were fewer in the 5- vs 10-day course (odds ratio, 0.79; 95% confidence interval, 0.63-0.98). This meta-analysis was limited by heterogeneity in the entry criterion of symptom duration (any patient with symptoms <30 days with positive radiological findings). Furthermore, there was overlap in the treatment duration of the comparison groups, with the long-course group including 6- and 7-day treatments and the short-course group also including 7-day treatments. The optimal duration of therapy remains to be definitively validated by clinical trials.

Treatment failure is defined as progression of symptoms at any time during treatment or failure to improve after 7 days of therapy.⁵ Patients in whom first-line therapy with amoxicillin fails or who relapse within 6 weeks require an alternative antibiotic with a broader spectrum. Fluoroquinolones (250 mg/d) or high-dose amoxicillin-clavulanate (4 g/d) may be considered.³ If an odontogenic source is identified, enhanced coverage of anaerobes and gram-negative bacteria is indicated.⁵⁶ For refractory cases, specialty referral to an otolaryngologist may be beneficial for obtaining endoscopic cultures to guide therapy.

A wide variety of over-the-counter remedies have been offered for symptomatic relief of acute rhinosinusitis. On the whole, no adjunctive therapy has been proven to shorten the duration of illness. However, these treatments are generally well tolerated and may be beneficial for patients who, like Mrs D, can be managed with watchful waiting.

Decongestants. Topical decongestants such as oxymetazoline are more effective than oral decongestants such as pseudoephedrine, although both forms are likely to alleviate symptoms.^{57 - 58} There is grade C evidence but no RCT to support their use.⁵ Patients using topical decongestants should be cautioned against prolonged use of medication (>5 days) to avoid the risk of rebound rhinitis.⁵⁹

Corticosteroids. Topical nasal corticosteroids reduce inflammation of the nasal mucosa and may have possible efficacy in treating acute rhinosinusitis. A 2007 Cochrane review supported the use of topical nasal corticosteroids as monotherapy or adjuvant therapy to antibiotics³² based on a meta-analysis of 4 double-blind, placebo-controlled trials. Currently, there is no US Food and Drug Administration–approved indication for the use of topical corticosteroids in acute rhinosinusitis. As with the studies of antibiotics in ABRS, published reports investigating topical corticosteroids should be interpreted carefully because they are often based on heterogeneous patient populations (acute, chronic, and/or viral rhinosinusitis) and treatment regimens (concomitant decongestant, saline irrigation, antibiotic). More well-designed clinical trials are needed to definitively validate the routine use of topical nasal steroids in acute rhinosinusitis. There is no evidence to support the routine use of oral corticosteroids for acute rhinosinusitis.

Antihistamines. Studies evaluating the role of antihistamines in acute rhinosinusitis comprise only grade D evidence.⁵ Antihistamines may have a minor role in treating atopic patients with acute rhinosinusitis and are not indicated in nonatopic patients.^{33 ,60} In Mrs D's case, her symptoms are more suggestive of an infectious etiology than an atopic etiology; therefore, antihistamines are not indicated.

Saline Irrigations. Buffered isotonic saline may be delivered to the nasal cavity by active (squeeze bottle) or passive (Neti pot) means. The mechanical cleansing of the nasal cavity has been shown to be beneficial in patients with recurrent acute sinusitis, chronic rhinosinusitis, and allergic rhinitis,^{34 ,61 - 62} but no studies have been done in patients with ABRS alone. Clinical guidelines neither advocate nor discount the use of irrigations.⁵ Given its low adverse effect profile, saline irrigation may be beneficial for patients seeking self-care options to supplement pharmacotherapy.

Complications of AVRS are uncommon, but specific rates are difficult to quantify because many cases of AVRS do not come to medical attention. While transient hyposmia is common in AVRS, permanent anosmia may also occur rarely.⁶³ Women may be disproportionately affected by viral-induced smell disturbances compared with men; women represented 67% of patients presenting with viral-induced olfactory loss to a major smell and taste clinic.⁶⁴ The most common complication of AVRS is secondary bacterial infection resulting in ABRS.¹⁰

Although the incidence of complications in ABRS is rare, estimated at 1 in 1000,³⁸ all patients with ABRS should be screened for the possibility of an underlying infectious complication. Complications of ABRS may be associated with significant morbidity or even mortality. The primary sites involved in complicated ABRS are the orbits and central nervous system, typically by direct extension (Figure 4). Orbital infections may range from preseptal cellulitis to subperiosteal abscess to orbital abscess, typically transmitted from the ethmoid sinus across the medial orbital wall.⁶⁵ Orbital extension may lead to cavernous sinus thrombosis. Acute sphenoid sinusitis or frontal sinusitis may be associated with CNS complications ranging from meningitis to epidural abscess or frank brain abscess.⁶⁶ Physical findings suggestive of a complication may include periorbital edema, disconjugate gaze, disorientation, or prostration. Any patient with ABRS who presents with visual symptoms, severe headache, somnolence, or high fever should be evaluated radiologically with an emergent sinus CT scan with contrast.²⁹ While there is no indication for surgery in patients with uncomplicated ABRS, surgery may be emergently indicated in patients experiencing extrasinus complications of ABRS.

Mrs D presents with a 5-day history of symptoms that is consistent with acute rhinosinusitis. The possibility of ABRS exists, but given the relatively early stage of presentation, it is not possible to readily distinguish between AVRS and ABRS. Given that her symptoms appear to be mild to moderate in severity, I would favor treating for 5 more days with symptomatic measures, such as topical decongestant sprays, oral decongestants, over-the-counter analgesics, and saline irrigations. If she improves, the presumptive diagnosis would be AVRS or spontaneously resolving ABRS. She should be instructed to contact her physician in the meantime if she develops a fever or her symptoms otherwise worsen. Particularly in light of her husband's immunocompromised state, she should wash her hands frequently to avoid transmitting infection.

If Mrs D reached the day 10 cut point without improvement in her symptoms, I would prescribe oral amoxicillin for 10 days for presumed ABRS. I would expect near-complete resolution by the end of the 10-day course of antibiotics. If she were to have lingering or worsening symptoms after 10 days of amoxicillin, I would extend therapy for an additional 10 days using amoxicillin/clavulanate or a respiratory fluoroquinolone. At that point, I would consider obtaining endoscopic cultures as well to guide therapy.

QUESTION: A lot of patients present like this patient and say that they’ve had multiple episodes of sinusitis and they get better only after antibiotics. What do you tell them?

DR HWANG: It's certainly possible that such a patient may have true recurrent ABRS, but this diagnosis can be difficult to distinguish from recurrent viral rhinitis or viral sinusitis. If a patient with recurrent viral sinusitis has received antibiotics on the fifth day of symptoms every time they’ve presented to their physician, then that patient might associate the receiving of antibiotic to the resolution of their disease. In actuality, the natural course of this patient's disease process dictates that symptoms would have resolved on their own regardless of antibiotic intervention.

In my practice, I would perform a nasal endoscopy to evaluate for purulent discharge or anatomic abnormalities that might be predisposing the patient to recurrent infections. If the endoscopy results were normal, I would encourage the patient to forgo antibiotics at the time of the next exacerbation, under my close supervision. As we educate our patients about the differences between viral and bacterial infections, they become comfortable with the notion of not receiving antibiotics. And while some patients will manifest true recurrent ABRS, many patients will find that their disease process resolves without antibiotics.

QUESTION: Are there normal bacterial flora in the sinuses? What are the defenses that prevent either the normal flora or other organisms from turning into a sinusitis? Are there defensins or other local products that are secreted? And is there more mechanistic information about what gets disrupted when there is a viral infection?

DR HWANG: That's a great question. Colonizing bacteria have been isolated from the sinuses, but we do not expect to encounter the pathogens typically associated with ABRS, such as S pneumoniae, H influenzae, or M catarrhalis.⁶⁷ In addition, the nasal vestibule is heavily colonized with bacteria. A simple nasal swab taken for the purpose of sinus culture will likely be contaminated by vestibular flora without yielding true pathogens. In contrast, an endoscopically derived culture specifically targeting deeper areas of the nose will have much greater yield. Thus, I recommend that all sinus cultures be obtained endoscopically.

In terms of local defenses against infection, mucociliary clearance is the primary macroscopic defense against particulate penetration of the sinus cavities. At a microscopic level, the sinonasal mucosa also demonstrates innate immune functions that maintain the protective barrier of the intact epithelium. Endogenous agents such as toll-like receptors, defensins, and nitric oxide may have important local immune functions. A viral insult may disrupt local immunity by overwhelming the milieu with toxic cytokines and degranulation products of white blood cells.⁵⁵ Injury to the epithelial barrier may disrupt both ciliary function and local immune surveillance, thereby predisposing to bacterial superinfection.⁵⁶

QUESTION: Could you comment further about the guideline recommendations for amoxicillin as first-line therapy? Would that change if the person were immunocompromised or had other comorbid conditions that could complicate the potential flora? There are certainly some limitations to the spectrum of coverage of amoxicillin.

DR HWANG: Absolutely. The recommendations discussed today apply to immunocompetent individuals with mild to moderate sinusitis. If you are treating a transplant patient or a patient with diabetes with a more severe clinical presentation of acute sinusitis, it is likely that your threshold for intervention will be lower. If the patient has severe symptoms, you may not choose to wait 10 days to begin antibiotic therapy, and I think it would be very reasonable to broaden your coverage beyond amoxicillin. One may see a higher incidence of amoxicillin-resistant organisms such as β-lactamase–producing H influenzae, methicillin-resistant S aureus, or even Pseudomonas. If you do not see a clinical response after the first few days of therapy, you may wish to consult an otolaryngologist for endoscopy and culture for precise identification of the pathogen and its antibiotic sensitivities.