| Acute sinusitis |
Click on any of the headings or subheadings to rapidly navigate to the relevant section of the guidemap
How does one know when bacterial sinusitis occurs during an acute viral rhinosinusitis?
When is antibiotic therapy indicated for bacterial sinusitis?
Which antibiotic should be used to treat acute bacterial sinusitis?
Are other therapeutic agents useful in the treatment of acute bacterial sinusitis?
What serious complications can occur in a patient with acute bacterial sinusitis?
When should a patient be referred to a otolaryngologist (ENT specialist)?
Commentary, criticism and controversy
This medical guidemap is focused on the common clinical problem of acute sinusitis. Sinusitis is one of the most frequently diagnosed medical conditions in office-practice in the USA, and millions of US patients receive antibiotic treatment for this condition every year. A layperson may presume that the indications for prescribing antibiotics in acute sinusitis are clear-cut and well-supported by clinical studies. Unfortunately, this is not the case, and expert researchers cannot even agree on a standard definition of bacterial sinusitis. This medical guidemap will carefully dissect this controversial issue, so that a layperson reader can more clearly discern when antibiotic therapy is indicated for the treatment of sinusitis.
This medical guidemap is only focused on the clinical problem of acute sinusitis, and I will not deal with the clinical problem of chronic sinusitis, which usually requires long-term management by an otolaryngologist (ENT specialist). The major focus of this medical guidemap will be on the issue of antibiotic therapy for acute sinusitis -- when is antibiotic therapy appropriate, which antibiotic choices are optimum, and for how long should antibiotics be prescribed. I will also discuss the symptomatic therapy of sinusitis, but in lesser detail.
Before I describe how sinusitis develops, I would like layperson readers to be aware of the standard definitions of bacterial sinusitis used in medical practice.
Acute sinusitis
Inflammation of the paranasal sinuses lasting less than 30 days. The inflammation is most commonly caused by a viral infection, and less commonly by a primary or secondary bacterial infection of the sinuses.
Acute bacterial sinusitis
Bacterial infection of the paranasal sinuses lasting less than 30 days in which symptoms resolve completely.
Subacute bacterial sinusitis
Bacterial infection of the paranasal sinuses lasting between 30 and 90 days in which symptoms resolve completely.
Recurrent acute bacterial sinusitis
Episodes of bacterial infection of the paranasal sinuses, each lasting less than 30 days and separated by intervals of at least 10 days during which the patient is asymptomatic.
Patients with recurrent acute bacterial sinusitis are defined as having had 3 episodes of acute bacterial sinusitis in 6 months or 4 episodes in 12 months. The response to antibiotics is usually brisk and the patient is completely free of symptoms between episodes.
Chronic sinusitis
Episodes of inflammation of the paranasal sinuses lasting more than 90 days. Patients have persistent residual respiratory symptoms such as cough, rhinorrhea (rynny nose), or nasal obstruction.
The paranasal sinuses are air-filled cavities in the face and skull bones, and they are lined by mucosa, which is similar to the mucosa lining the inside of the nasal passages and upper respiratory tract. The sinuses constantly produce sinus fluid from mucosal glands and this fluid drains into the nasal cavity through small openings called ostia. There are 4 major groups of sinuses. The first group of sinuses is found in the maxillary bones of the face (cheekbones), and they are called the maxillary sinuses. The ethmoid sinuses are found in the ethmoid bones between the eye orbits and there are approximately 3-18 ethmoidal cells. The frontal sinuses are found in the frontal bones just above the orbits. The sphenoid sinus is found deeper in the skull in an area just behind the ethmoid sinuses. Only the maxillary and ethmoid sinuses are present at birth and they enlarge during the first decade of life. The frontal and sphenoid sinuses only begin to appear at 5-6 years of age, and they do not become fully developed until adolescence. The maxillary sinus and the anterior (front) ethmoidal sinus on each side drain into the middle section of each nasal cavity through an opening called the osteomeatal complex, which is found underneath the middle turbinate bone (concha). The frontal, sphenoid and posterior (back) ethmoidal sinuses drain into the upper part of the nasal cavity on each side, through an opening just below the superior turbinate bone (concha).
Photographs are from an excellent ENT website at http://www.ghorayeb.com
The lining of the sinuses can become inflammed by chemical or infectious agents. The most frequent cause of an acute sinusitis is the "common cold" (upper respiratory tract infection) which is due to a viral infection. During a "common cold" viruses invade and inflame the lining of the nose, the upper respiratory tract and the sinuses simultaneously. Inflammation of the nose is referred to as rhinitis and inflammation of the sinuses is referred to as sinusitis. The "common cold" should therefore be thought of as being an acute rhinosinusitis due to a virus infection. The viruses causing a "common cold" enter the sinuses through the ostia and inflame the mucosal lining of the sinuses. The mucosal lining becomes swollen and thickened as a result of the inflammatory response, and the sinuses become filled with fluid that arises from leakage of serous fluid from blood vessels within the mucosa and from mucosal glands that actively secrete fluid. Normally this fluid drains through the sinus openings into the nasal passages. The epithelial cells lining the sinuses are ciliated, and the cilia beat in the direction of the sinus ostia. The constantly moving cilia sweep mucus fluid and debris (containing viruses and damaged epithelial cells) towards the sinus openings. The sinuses do not drain by gravity, but as a result of the active ciliary movement, which sweep constantly in the direction of the sinus openings. Damage to the cilia as a result of the virus infection impairs the ability of the sinuses to drain. The sinuses also cannot drain adequately if the sinus ostia become blocked at the site of their opening into the nasal passages by swollen nasal mucosa. If the sinus openings become obstructed, the problem perpetuates itself, because the viruses are trapped in the sinuses and they continue to damage the sinus mucosal lining. Under normal conditions, the sinuses are bacteriologically sterile because any bacteria that transiently enter the sinuses from the nasal passages are constantly swept out of the sinuses by the ciliary activity. A bacterial sinusitis develops if the sinus ostia become obstructed during a viral rhinosinusistis ("common cold") and the trapped bacteria multiply in the sinus cavities. A bacterial sinusitis develops when the density of bacteria exceeds a certain arbitrary number. Accordingly, the gold standard definition of bacterial sinusitis is the recovery of bacteria in high density (100,000 colony-forming units/mL) from the cavity of a paranasal sinus.
Most acute sinus infections involve more than one paranasal sinus, and usually only the maxillary and ethmoid sinuses are involved. The frontal and sphenoid sinuses are rarely involved in acute viral rhinosinusitis. Isolated sinusitis affecting either the frontal or sphenoid sinus is very rare and usually bacterial in origin, and they are associated with a high complication rate (spread of the infection to the skull or brain).
Although a virus infection precedes 80% of cases of acute bacterial sinusitis, there are other causes of bacterial sinusitis. Bacterial sinusitis can develop whenever the sinus ostia are obstructed, thus preventing the sinuses from draining normally. The second most common cause of sinus ostial obstruction is due to the swollen nasal mucosa found in allergic rhinitis, which accounts for approximately 20% of acute sinusitis episodes (and a much greater percentage of chronic sinusitis episodes). The other causes of sinus ostia obstruction are far less common and include nasal foreign bodies (eg. plastic beads that children love to insert into their nasal passages), a deviated nasal septum, nasal mucosal polyps, and nasal tumors. Occasionally bacterial sinusitis develops secondary to direct bacterial invasion from a nearby anatomical site (eg. from a dental infection involving the maxillary teeth) without any primary event obstructing the sinus ostia. Bacterial sinusitis can also develop in paients with certain immunological disorders (eg. congenital immunodeficiency syndromes, HIV infection), chronic mucosal disorders (eg. cystic fibrosis) or rare ciliary disorders (eg. primary cilia dyskinesia, immotile cilia syndrome). Those conditions are more likely to cause chronic sinusitis, and they are usually discovered during the diagnostic workup of chronic sinusitis. Interstingly, no convincing evidence exists to support the role of environmental pollutants and toxicants in causing or prolonging sinusitis.
What is the natural course of acute viral rhinosinusitis?
There are many viruses that cause the "common cold" and they usually invade the nasal cavities and upper respiratory tract. Initial symptoms include a mild fever, sore or scratchy throat, rhinorrhea (runny nose), sneezing, and nasal congestion. A mild cough can also be present in 60-80% of cases due to direct irritation of the upper airways and due to a post-nasal discharge. Malaise, headache, body aches, and anorexia can accompany the illness. The watery nasal secretions usually become thicker 1-3 days after the start of the illness, and often become mucopurulent in appearance. The presence of a thick yellow purulent nasal discharge does not necessarily imply a bacterial infection, and it is simply due to the presence of desquamated epithelial cells and live/dead white blood cells. The duration of the illness varies between 2-10 days. Although most patients improve within 10 days, some patients (up to 25-30%) have lingering symptoms (nocturnal cough, nasal discharge, nasal stuffiness) for longer than 2 weeks. The sinuses are always involved in acute viral rhinosinusitis, and the patient may complain of a sense of fullness, or pressure, or pain in the area of the sinuses -- cheeks (maxillary sinuses), between the eye orbits (ethmoid sinuses) and above the orbits (frontal sinuses). The sense of sinus fullness/pressure may be affected by the position of the head, and can be worse when the patient stoops forward. The sinuses may be variably tender to palpation, but this is a non-specific sign. Sinus pressure symptoms are to be expected during an acute viral rhinosinusitis, and their presence does not imply a bacterial sinusitis.
How does one know when bacterial sinusitis occurs during an acute viral rhinosinusitis?
Children frequently suffer from a "common cold", and the average child gets 3-6x "common cold" infections per year. How many of those "common cold" episodes are followed by an episode of bacterial sinustitis? I have seen different figures in the medical literature -- some experts state that a bacterial sinusitis complicates 0.5-5% of pediatric "common cold" infections, while other experts quote higher prevalence figures of 3-13%. The figure for adults is approximately 0.5-2%.
How does one know when a bacterial sinusitis is complicating an acute viral rhinosinusitis? There is no perfect answer to that question, because one could only discover that a bacterial sinus infection is present if one aspirated fluid from the sinuses and checked the sinus fluid for the presence of bacteria in every patient with an acute viral rhinosinusitis. However, sinus aspiration is a painful procedure and rarely performed. A few research studies have been performed in children who had prolonged "common cold" symptoms (>14 days) -- sinus X-rays demonstrated fluid-filled sinuses in about 80% of those children, and sinus fluid was aspirated from all children with positive X-ray findings. A bacterial infection was found in 70% of those patients. Therefore, the researchers concluded that 56% (0.8x0.7) of children with prolonged "common cold" symptoms lasting longer than 10-14 days, had bacterial sinusitis. Those types of research studies form the basis of the definition of one category of bacterial sinusitis -- that which occurs in patients with an acute viral rhinosinusitis that persists for longer than 10-14 days. The symptoms can include nasal and/or sinus congestion, a nasal or post-nasal discharge (of any quality), and a daytime cough (which can be worse at night). Halitosis (foul breath) may or may not be present. The patient usually does not feel well but does not appear toxic. Fever usually is not present but, if present, usually is low grade. Only about 50-60% of patients with persistent rhinosinusitis symptoms can be expected to have a bacterial sinusitis -- based on the results of a number of clinical studies. The clinical likelihood of bacterial sinusitis is significantly greater if unilateral maxillary pain and maxillary dental pain is also present. Unfortunately, the physical examination does not generally contribute substantially to the diagnosis of acute bacterial sinusitis. This is explained by the similarity of physical findings in the patient with an uncomplicated viral rhinosinusitis and the patient with a superadded acute bacterial sinusitis. In both situations, examination of the nasal mucosa may show mild redness and swelling of the nasal turbinates and a non-specific mucopurulent nasal discharge.
Another clinical method of deciding that an acute rhinosinusitis patient has developed a bacterial sinusitis infection is based on the severity of the symptoms. Severe symptoms suggestive of a bacterial infection include a high fever of at least 102°F or 39°C, and the presence of a concurrent purulent nasal discharge for at least 3-4 consecutive days. Facial pain (unilateral or predominantly unilateral), dental pain involving the maxillary teeth (teeth of the upper jaw) and peri-orbital swelling (swelling around the orbits with no redness) may also be present. A severe headache may be present above and behind the eyes. Contrast that clinical scenario with an uncomplicated viral rhinosinusitis infection. If fever is present at all in uncomplicated viral rhinosinusitis, it tends to be mild in degree and present early in the illness, and the mild fever is usually accompanied by constitutional symptoms such as headache and muscle aches. Generally, the constitutional symptoms resolve in the first 48 hours, and then the respiratory symptoms become more prominent. In most uncomplicated viral rhinosinusitis infections, the nasal discharge only becomes purulent after a few days. By contrast, it is the concurrent presence of a high fever and purulent nasal discharge for at least 3-4 days that defines a severe bacterial sinusitis. The presence of face pain, dental pain (in the absence of dental pathology), and/or peri-orbital swelling (occasionally seen in ethmoidal sinusitis) makes the diagnosis of bacterial sinusitis even more likely. It is important to realize that classic symptoms/signs of a severe sinusitis infection are rarely found in young children, and that face pain and tenderness are rare complaints.
Occasionally, isolated sinusitis may develop without any antecedent viral rhinosinusitis. One example of isolated sinusitis, would be the development of unilateral (one-sided) maxillary sinusitis secondary to a nasal foreign body. Children often push plastic beads into their nasal passages, and the bead can obstruct the maxillary ostia on that side. The major clue to an unilateral sinus infection would be the presence of a foul-smelling nasal discharge from one nostril, +/- pain in the cheek on the affected side +/- fever. An astute observer may note, after removal of the bead, that the pus is draining from the osteomeatal complex area just below the middle turbinate bone. A purulent nasal discharge that is isolated to this area is strongly suggestive of sinusitis. In bacterial sinusitis secondary to an acute viral rhinosinusitis, it is very difficult to determine where any pus is coming from, because the nasal mucosa inside the nasal passages is so swollen that it obscures the field of vision.
When is antibiotic therapy indicated for bacterial sinusitis?
Clinical indications for the treatment of suspected bacterial sinusitis
Empiric antibiotic therapy is indicated if bacterial sinusitis is strongly suspected:- i) because an acute viral rhinosinusitis patient has persistent URI symptoms lasting longer than 10-14 days, or ii) because the patient develops severe symptoms suggestive of bacterial sinusitis in the presence (or absence) of an antecedent acute viral rhinosinusitis. Bacterial sinusitis presenting with more severe rhinosinusitis symptoms is much less common than bacterial sinusitis presenting with persistent, unimproved URI symptoms.
It is important to remember that only 0.5-5% of "common cold" patients develop acute bacterial sinusitis, and that it would represent poor quality medical practice if a physician indiscriminately treated all his "common cold" patients with antibiotics. A physician should only use antibiotics for persistent rhinosinusitis symptoms if they last longer than 10-14 days. Up to 20-30% of "common cold" patients have persistent rhinosinusitis symptoms lasting longer than 10-14 days, and only about half of those patients actually have a bacterial sinusitis. Therefore, the best policy that a physician could adopt during the first 10 days of an acute viral rhinosinusitis infection is the policy of "watchful waiting" to see if the symptoms persist or worsen. Antibiotic therapy is only appropriate if symptoms persist (last longer than 10-14 days) or become more severe (fever + concurrent purulent nasal discharge + face pain + maxillary dental pain).
Contrary expert opinion -- some clinician-experts believe that patients, who do not have the additional symptoms of maxillary facial and/or teeth pain and an accompanying purulent nasal drainage, are unlikely to have bacterial sinusitis, regardless of the duration of the illness. They therefore only recommend antibiotic therapy for patients with persistent rhinosinusitis symptoms lasting longer than 10-14 days if maxillary face/teeth pain and a purulent nasal discharge are also present.
Diagnostic testing to determine whether bacterial sinusitis is present
Sinus X-rays
Some physicians order sinus X-rays to establish whether an acute URI patient has sinusitis. Sinus X-rays have no real value in this context. First of all, the sinus X-rays frequently demonstrate radiological signs of sinusitis (mucosal thickening, an air-fluid level due to a partially fluid-filled sinus, or sinus opacification due to a completely fluid-filled sinus) early in the course of an acute viral rhinosinusitis, but those radiological signs do not imply a bacterial infection. As many as 80% of acute viral rhinosinusitis patients may have radiological findings suggestive of sinusitis early in their disease course, and most of those findings resolve spontaneously. It is only after 10-14 days that a positive sinus X-ray is more suggestive of a bacterial sinusitis. However, there is no need for a physician to order sinus X-rays if acute rhinosinusitis symptoms are persistent (>10-14 days), because those patients should be treated empirically with antibiotics on clinical grounds alone. Sinus X-rays may be appropriate in patients with an equivocal history suggestive of isolated sinusitis. Another important fact about sinus X-rays, is that sinus abnormalities are often found in 30-40% of asymptomatic people, and their presence does not imply the presence of a sinus infection if sinusitis symptoms are absent. Also, some patients with active sinusitis have normal sinus X-rays. Therefore, sinus X-rays are neither sensitive or specific for the presence, or absence, of sinusitis. Another disadvantage of sinus X-rays is that they are difficult to interpret -- especially with respect to the ethmoid and frontal sinuses -- and there are many false-negative and false-positive X-ray readings, especially in children. It is also technically very difficult to get good quality radiographs in very young children because they are less able to maintain the correct positioning during the radiographic procedure.
CT scan of the sinuses
A CT scan of the sinuses is the best radiological study for demonstrating the anatomy of the sinuses. However, it is also of no value early in the disease course of an acute viral rhinosinusitis, because it is often abnormal, and an abnormal CT scan does not imply a bacterial sinusitis infection. A CT scan of the sinuses is specifically indicated if the patient develops clinical signs suggestive of a complicated acute sinus infection:- i) if clinical signs suggest that the sinus infection is extending to areas outside the sinuses (eg. eye orbit or cranial cavity); ii) if an ENT specialist plans to perform a sinus aspiration procedure or sinus surgery because a patient's sinusitis is refractory to antibiotic therapy.
Click here to see photographs of plain X-rays and CT scan images of maxillary sinustis
Blood tests
Blood tests (eg. complete blood count, sed rate) have no value in determining whether a sinusitis patient has bacterial sinusitis.
Nasal or throat culture
A culture of any nasal discharge, or post-nasal discharge, or throat exudate has no value, because even if the culture is positive for bacteria , there is no correlation between a positive nasal or throat culture and a culture of sinus fluid obtained by aspiration. The "gold standard" culture that needs to be performed to verify the presence of a bacterial sinusitis is a culture of fluid from a sinus aspirate. However, sinus fluid aspiration is rarely perfomed because it is painful and invasive, and it is usually only performed by an ENT specialist if the patient has a persistent sinusitis that is unresponsive to antibiotics, or if the sinusitis is severe and progressive, or if the sinus infection spreads beyond the boundary of the sinuses (complicated sinusitis). A microswab culture of the nasal discharge from the area of the osteomeatal complex under the middle turbinate bone correlates 80-85% of the time with a maxillary sinus culture, but it requires specialized endoscopic skill with a rhinoscope (an instrument that an ENT specialist uses to view the inside the nose) to obtain that type of culture.
In summary, the decision to treat a sinusitis patient with antibiotics is usually made on clinical grounds, and it is rare that the clinical diagnosis of bacterial sinusitis is absolutely certain. Most sinusitis patients who are treated with antibiotics, are treated empirically, without any sinus culture-proof that the infection is truly bacterial.
Which antibiotic should be used to treat acute bacterial sinusitis?
Most cases of acute bacterial sinusitis are due to one of the following three bacterial organisms:- Streptococcus pneumoniae (SP), Hemophilus influenzae (HI) or Moraxella catarrhalis (MC).
Staphylococcus aureus bacteria are usually only found in sinusitis following sinus surgery or trauma. Gram negative and anaerobic bacteria are mainly found in nosocomial sinusitis (eg. sinusitis that develops in ICU patients who have naso-gastric tubes or endotracheal tubes residing in their nasal passages) or in chronic sinusitis.
Because acute bacterial sinusitis is overwhelmingly caused by those 3 common bacterial organisms (SP, HI, MC), antibiotic therapy should be specifically targeted at those bacteria. Amoxicillin is the first antibiotic-of-choice in nearly all cases of adult and pediatric acute bacterial sinusitis, if the patients have have no risk factors suggesting the presence of antibiotic-resistant bacterial organisms. The standard dose of amoxicillin is 45mg/kg/day in three divided doses. However, SP bacteria in the USA are becoming increasingly resistant to amoxicillin and other antibiotics. About 25-40% of SP bacteria (also called the pneumococcus bacteria) are resistant to penicillin in the USA, and 50% of those bacteria are highly resistant, while the other 50% have intermediate resistance. To combat beta-lactamase-resistant HI/MC bacteria and highly resistant SP bacteria, amoxicillin is combined with clavulanic acid, and administered in much higher doses. High dose amoxicillin kills resistant SP bacteria while the added clavulinic acid component kills beta-lactamase resistant HI/MS bacteria. Many physicians would therefore use a higher dose of amoxicillin clavulanate (80-90mg/kg/day) as primary therapy if antibiotic-resistant organisms are strongly suspected or if the sinusitis infection is clinically severe. Reasons to suspect the presence of antibiotic-resistant SP bacteria include:- i) recent epidemiological evidence of a high prevalence of antibiotic-resistant SP in the local community; ii) children who attend day care; iii) children who are <2 years of age; iv) recent (within 3 weeks) use of antibiotics; and v) inadequate clinical response within 2-3 days to standard doses of amoxicillin. High dose amoxicillin-clavulanate therapy is expensive and frequently causes diarrhea (up to 30%), but this can be decreased by strictly giving the antibiotic every 8 hours and administering it with food. Most acute bacterial sinusitis patients show a good response to effective antibiotic therapy within 2-3 days of starting therapy and approximately 80% of patients should respond to antibiotic therapy by the 10th day. (Interestingly, in placebo controlled clinical trials of patients with persistent rhinosinusitis symptoms, 40-60% of similarly affected patients respond to placebo therapy by the 10th day of treatment -- either because they do not really have a bacterial sinusitis, or because their bacterial infection resolves spontaneously). The optimum duration of antibiotic therapy has never been proven in clinical trials, but a consensus opinion is that antibiotic therapy should be given for a minimum of 10 days, or for at least 7 days after resolution of the symptoms. A second-line antibiotic should be prescribed if the patient does not significantly improve within 2-3 days.
Despite the increasing problem of antibiotic resistance in the USA, amoxicillin is still favored as first-line therapy because of its well-established history of general effectiveness, safety, tolerability, and low cost. Other antibiotics -- trimethoprim-sulfamethoxazole or erythromicin-sulfasoxazole -- were used in the past for penicillin-allergic patients, but those drugs are no longer favored because SP, HI and MC bacteria are increasingly resistant to those antibiotics.
If the patient is allergic to amoxicillin and the previous allergic reaction was not an immediate type 1 hypersensitivity reaction, a second-generation cephalosporin such as cefdinir (14 mg/kg/day in 1 or 2 doses), cefuroxime (30 mg/kg/day in 2 divided doses), or cefpodoxime (10 mg/kg/day once daily) can be used. In patients with a history of a serious type 1 hypersensitivity allergic reaction to penicillin, clarithromycin (15 mg/kg/day in 2 divided doses) or azithromycin (10 mg/kg/day on day 1, 5 mg/kg/day × 4 days as a single daily dose) can be used in an effort to select an antimicrobial of an entirely different class (macrolide class). Alternative antibiotic therapy for the penicillin-allergic patient, who is known to be infected with a penicillin-resistant SP bacteria, is clindamycin at 30 to 40 mg/kg/day in 3 divided doses. A single dose of ceftriaxone (at 50 mg/kg/day), given either intravenously or intramuscularly, can be used if recurrent vomiting precludes the administration of oral antibiotics. An oral antibiotic can used to complete the course of therapy if the patient is clinically improved 24 hours later and is subsequently able to tolerate an oral antibiotic. In patients with dental causes of sinusitis or those with a foul-smelling discharge, a physician should strongly consider an antibiotic with good anaerobic coverage (eg. clindamycin, or amoxicillin with metronidazole).
If the patient does not fully respond to the first course of amoxicillin therapy, a second 10-14 day course of another antibiotic is usually prescribed. The most commonly used second-line therapies include high-dose amoxicillin clavulanate, second-generation cephalosporins (eg, cefuroxime, cefpodoxime), macrolides (eg, azithromycin, clarithromycin), fluoroquinolones (eg, ciprofloxacin, levofloxacin), and clindamycin. Fluoroquinolones should not be used in children under the age of 18 years because of safety concerns. For patients who do not improve after a second course of antibiotics, or who are acutely ill, two treatment options are commonly utilized. The one option is for the family physician to consult an ENT specialist for consideration of maxillary sinus aspiration in order to obtain a sample of sinus fluid for culture and sensitivity, so that antibiotic therapy can be appropriately adjusted. Alternatively, the family physician may decide to prescribe intravenous cefotaxime or ceftriaxone (either in hospital or at home) and only consult an ENT specialist if the patient does not improve on intravenous antibiotics.
Are other therapeutic agents useful in the treatment of acute bacterial sinusitis?
Many other therapeutic agents (especially over-the-counter medications) are prescribed in patients with acute sinusitis, although there is no solid scientific evidence to support their use.
Antihistamines
Older generation H1 antihistamines are recommended in patients with a "common cold" to relieve the symptoms of sneezing, watery rhinorrhea and nasal stuffiness. They work by thickening and drying the nasal secretions as a result of their anticholinergic action (and not because they inhibit histamine). Antihistamines have the theoretical disadvantage that thickened nasal secretions may clog the sinus ostia and impede sinus drainage, thus predisposing the patient to a secondary bacterial sinusitis. Antihistamines are therefore only definitely appropriate if the sinusitis is secondary to an allergic rhinitis infection, because they inhibit the effect of histamine released during the allergic reaction. The antihistamine effect is clinically useful, because it significantly decreases the amount of sneezing, nasal mucosal swelling, and watery nasal discharge. In that situation, newer generation, non-sedating antihistamines should be chosen to prevent the side-effect of excessive drowsiness. However, newer generation antihistamines are not effective decongestants in patients with a common cold (acute rhinosinusitis), presumably because of their limited anticholinergic activity. They should therefore not be used in patients with acute infectious rhinosinusitis.
Decongestants
Oral decongestants (eg. pseudoephedrine, phenylephrine) are also frequently prescribed in patients with a "common cold", although they are not as effective as topical decongestants (eg. topical nasal sprays containing oxymetazoline or phenylephrine) in shrinking the swollen nasal mucosa. Topical decongestants work very well in the first few days of a "common cold" and they significantly reduce nasal stuffiness and watery rhinorrhea. By analogy, topical decongestants should theoretically work in acute bacterial sinusitis, that is secondary to acute viral rhinosinusitis, by reducing the obstruction of the sinus ostia by swollen nasal mucosa. However, many experts believe that they cannot really work if they are not applied directly to the area of the osteomeatal complex, which is usually impossible to achieve if the entire nasal mucosa is so swollen that the area of the osteomeatal complex is effectively obscured. Also, topical decongestants should only be used for 3-5 days, because of a "rebound phenomenon" -- the nasal mucosa becomes even more swollen after a few days of continuous topical decongestant use (a condition called rhinitis medicamentosa) and the patient becomes refractory to continuous topical decongestant use. Therefore, if topical decongestants were used continuously for a few days early in the course of an acute viral rhinosinusitis, then they should not be used continuously later in the course of the illness if bacterial sinusitis develops, because they may paradoxically aggravate the swelling of the nasal mucosa and worsen the problem of impaired sinus drainage.
Mucolytic agents
Guaifenesin is the chief mucolytic agent used in the treatment of lower respiratory tract infections in order to liquify thick bronchial secretions. The same mucolytic agent -- guaifenesin -- has been frequently used in acute sinusitis with the hope that it would liquify thick nasal secretions. However, there is no scientific evidence that a mucolytic agent is effective in acute sinusitis.
Nasal steroid spray
Topical nasal steroid sprays have been shown to be effective in the treatment of allergic rhinitis, and they are therefore considered particularly useful for chronic sinusitis secondary to allergic rhinitis. However, they are of questionable value in the management of acute viral rhinosinusitis or bacterial sinusitis. Many physicians continue to prescribe nasal steroid sprays as an adjunct to antibiotic therapy, even though certain experts question their value.
Steam and heated mist
The modalities of steam, or heated mist (including delivery intranasally under pressure), have been studied in patients with allergic rhinitis and the common cold. However, none of this work has been extended to patients with sinusitis and there is no definite scientific evidence that it is truly helpful in the treatment of acute sinusitis.
Nonetheless, steam can be safely used if correctly applied, and patients can use steam inhalation therapy if it offers symptomatic relief.
The traditional method of steam inhalation is as follows:
1. Pour boiling water in a pan or basin on a low table.
2. Sit at the table with a towel draped over the head to make a tent
over the pan of water.
3. Hold the face a few inches above the water and breathe through the
nose for approximately 10 minutes.
This procedure may liquefy and soften crusts while moisturizing the dry, inflamed mucosa.
Many patients find that 2x treatments a day provides some symptomatic relief. If a patient is for some reason unable to perform this simple procedure, using a vaporizer or a facial sauna or taking long, hot showers may be beneficial, but none of these alternatives is thought to be a good substitute for the hot water and tent method. The ritual of boiling the kettle, preparing the tent, and relaxing over the steamy brew probably has a good psychologic effect, enhancing the therapeutic benefit. Patients, however, should not to breathe steam directly from a boiling kettle.
Saline irrigation
Saline irrigation is used to loosen thick nasal secretions and it may offer symptomatic relief of sinus pressure symptoms. Saline therapy may decrease crusting of secretions near the nasal ostia and prevent sinus ostia obstruction.
Patients can use homemade saline solution (1/4 teaspoon of salt dissolved in one cup of water, using a bulb syringe or dropper purchased from a drug store) or commercial saline nasal drops or nasal spray 2-3x per day.
Click here for free online access to an excellent monograph on over-the-counter (O-T-C) medications, titled "Appropriate Use of Common OTC Analgesics and Cough and Cold Medications" -- An American Family Physician Monograph. It has a particularly strong section on the potential adverse effects of O-T-C medications.
What serious complications can occur in a patient with acute bacterial sinusitis?
Most patients with acute bacterial sinusitis respond adequately to antibiotic therapy, and complications are very rarely seen in clinical practice. Because many family physicians have never encountered clinical cases where the sinus infection has spread to areas outside the sinus cavities (eg. orbit, skull or brain), they may miss clinical signs suggestive of early extra-sinus disease.
Spread to the orbit of the eye
Sinusitis can spread to the orbit, and produce an orbital infection. This usually occurs secondary to direct or hematogenous (blood stream) spread from an ethmoid sinusitis. The extent/intensity of the orbital infection can vary considerably, and a classification system is used to describe the extent of an orbital infection.
Preseptal (peri-orbital) cellulitis.
The orbital septum is a sheet of connective tissue continuous with the periosteum of the orbital bones that separates the tissues of the upper eyelid from those of the orbit. Preseptal (above the septum) inflammation involves only the upper eyelid, whereas postseptal (below the septum) inflammation involves structures of the true orbital cavity. The patient with preseptal cellulitis has swelling and redness of the upper eyelid +/- swelling of the peri-orbital (area surounding the orbit) region due to passive venous congestion. The patient can still elevate the swollen, red upper eyelid. The external eye often appears normal or slightly red, and the eye globe is not bulging. All eye movements are painless and complete, and vision is normal.
Orbital cellulitis
The infection has spread below the orbital septum into the orbital cavity, but the orbital infection has not yet produced an orbital abscess.
In orbital cellulitis the redness involves the whole peri-orbital area
around the eye, and not just the upper eyelid.
The external eye may be very red, but it is not proptotic (bulging
forward of the eye globe). External eye movements may be painful but they
are complete, and vision is normal. Fever may be present.
Orbital abscess
The infection within the orbit is extensive, and pus collects within the orbital cavity around the eye globe. The eye is pushed forward, and the abscess interferes with the extraocular eye muscles moving the eye, so that external eye movements are incomplete or absent (fixed globe). Diploplia (double vision) is an early symptom suggesting involvement of the extraocular eye muscles. Extensive disease may result in an immobile eye, proptosis (bulging forward of the eye globe), chemosis (red bulging conjunctival tissue) and impaired vision due to compression of the optic nerve within the orbit.
A CT scan of the orbit can clearly differentiate the extent of preseptal and postseptal orbital involvement, and is routinely ordered if post-septal orbital involvement is suspected.
Any involvement of the orbit (preseptal or postseptal) is a medical emergency and the patient should seek immediate medical attention.
A physician's initial approach to these orbital complications varies, but the usual clinical approach could be as follows:-
Mild cases of periorbital cellulitis (eyelid <50% closed) could be treated with appropriate oral antibiotic therapy as an outpatient with daily patient encounters. However, if the patient has not improved in 24 to 48 hours or if the infection is progressing rapidly, it is more appropriate to admit the patient to the hospital for antibiotic therapy consisting of intravenous ceftriaxone (100 mg/kg/d in 2 divided doses) or ampicillin-sulbactam (200 mg/kg/d in 4 divided doses). Vancomycin (60 mg/kg/d in 4 divided doses) may be added in children in whom infection is either known or likely to be caused by SP bacteria that are highly resistant to penicillin. If proptosis, impaired visual acuity, or impaired extraocular eye mobility are present on examination, a CT scan (preferably coronal thin cut with contrast) of the orbits/sinuses is essential to exclude a suppurative complication. In such cases, the patient should be promptly evaluated by an otolaryngologist and an ophthalmologist.
Spread to the intracranial cavity
Cavernous sinus thrombosis
A bacterial sinusitis infection can also spread from the ethmoid sinuses into the cranial cavity and affect a complex system of veins immediately behind the orbit called the cavernous sinus. Infection of the cavernous sinus can cause the blood inside the cavernous sinus to clot resulting in a cavernous sinus thrombosis, which presents clinically in a similar manner to an orbital abscess -- with incomplete eye movements due to involvement of the nerves innervating the external eye muscles, chemosis, and loss of vision. Meningeal signs (stiff neck), altered mental status and high fever may be present as well.
Cavernous sinus thrombosis often spreads to the other side via connecting venous channels, so that clinical signs of a bilateral cavernous sinus thrombosis occurs. Bilateral (both sides) involvement of the orbits suggests a cavernous sinus thrombosis, rather than an orbital abscess. A CT scan can readily differentiate a cavernous sinus thrombosis from an orbital abscess.
Brain abscess
Spread of infection from a frontal or ethmoidal sinusitis can result in a brain abscess in the frontal region of the cranial cavity. The abscess can exist within the brain tissue or in the space between the brain and the skull (subdural abscess or epidural abscess). Symptoms can include severe headache, fever, altered mental status, seizures, and focal neurological signs.
Meningitis
Meningitis can occur alone or meningitis can accompany other types of intracranial involvement eg. cavernous sinus thrombosis. The classical signs of meningitis include headache + fever + stiff neck +/- altered mental status.
Any intracranial spread of a sinus infection is a medical emergency and the patient should seek immediate medical attention. All patients with intracranial spread of a bacterial sinisutis infection should be treated in-hospital.
Spread to the skull bones.
The most common example of this would be Potts puffy tumor, which is the term used to describe an osteomyelitis (bone infection) of the frontal bone of the skull. This usually occurs secondary to direct spread from an isolated frontal sinusitis, and the patient presents with a doughy-feeling bulge of his forehead. The bulging area may also be red and tender. Osteomyelitis of the maxillary facial bone is less common.
Any involvement of the skull or facial bones, suggested by facial or forehead swelling and redness, is a medical emergency and the patient should seek immediate medical attention.
Useful emedicine.com chapters that provide detailed clinical information for health care professionals.
Pre-septal cellulitis
Orbital cellulitis
Cavernous sinus
thrombosis
When should a patient be referred to a otolaryngologist (ENT specialist)?
The primary care physician's threshold for referring a sinusitis patient to an ENT specialist depends on local community practice patterns.
Some indications for consulting an ENT specialist include:-
- if the patient doesn't respond adequately to two 10-14 days courses of antibiotics for "presumed" bacterial sinusitis
- if the patient's sinusitis symptoms persist, and subacute or chronic sinusitis occurs
- if the patient develops severe sinusitis, that doesn't respond promptly to antibiotic therapy
- if the patient has isolated frontal or sphenoid sinusitis that is moderate-severe, because of the significant potential for extra-sinus spread of the infection
- if the patient develops any evidence of extra-sinus spread of infection to the facial bones, skull bones, orbits, or intracranial cavity
- if the primary care physician discovers an intranasal tumor, or an intranasal foreign body that cannot be readily removed
- if the primary care physician discovers an anatomical defect that obstructs the sinus ostia (eg. deviated nasal septum)
- if the primary care physician discovers rare disorders that cause or mimic sinusitis eg. Wegeners granulomatosis, leprosy, fungal disorders (eg. mucormycosis or allergic aspergillosis).
Commentary, criticism and controversy
Insightful questions and comments from readers will be included in this section.
Disclaimer: My medical guidemaps reflect my personal
approach to clinical problems, and although my personal approach is primarily
based on a thorough evaluation of the evidence-based medical literature,
my personal approach should not be regarded as the "standard of care".
My medical guidemaps should only be used if the reader-user has substantial
reason to believe that the clinical advice contained in the guidemaps is
valid and accurate. My medical guidemaps do not represent a personal medical
service and they should not be used as a substitute for consulting a physician
or other health-care provider. My medical guidemaps should be perceived
as being an altruistic educational resource that is only applicable to
medical practice in the USA and certain other countries.