ABSTRACT: Better understanding of the multiple etiologies for acute and chronic sinusitis can lead to an individualized treatment plan.
CME OBJECTIVE: The reader will understand the etiology and pathophysiology of rhinosinusitis and how to develop a rational therapeutic approach.
Michael J. Sillers, MD, consultant Gyrus ENT, General Electric Medical Systems Navigation and Visualization, Inc., Explora Med, Inc., Priority Healthcare Corp.
Many of the 31 million Americans who experience rhinosinusitis each year seek antibiotics to treat their pain, swelling, nasal discharge, and anosmia. Yet, new guidelines defining diagnosis and treatment of rhinosinusitis indicate the drugs, which cost $3.5 billion annually in the United States, may not be treating underlying causes in a significant number of patients.
Rhinosinusitis, commonly known as sinusitis, is an inflammation of the mucous membranes of the nose and sinuses.
"The disorder has increased in prevalence and incidence in recent years, negatively impacting patients' quality of life and impairing daily functions," says UAB otolaryngologist Michael J. Sillers, MD, noting patients frequently request antibiotics when they experience chronic sinus pressure and pain. "But, these drugs often provide no benefit or may address only a single underlying factor. Clearly, existing definitions have failed to describe all manifestations of rhinosinusitis; it can be viral, bacterial, fungal, allergic, or of unknown origin."
Creating Consensus
Experts from the American Academy of Allergy, Asthma, and Immunology; American Academy of Otolaryngic Allergy; American Academy of Otolaryngology — Head and Neck Surgery; American College of Allergy, Asthma, and Immunology; and American Rhinologic Society formed a panel of 30 physicians to develop definitions of rhinosinusitis for clinical research and patient care. The panel reached a consensus and published their guidelines in two December 2004 journals (J Allergy Clin Immunol. 2004;114:155-212 and Otolaryngol Head Neck Surg. 2004;131[6 Suppl]: S1-S62).
"The panel adopted the term 'rhinosinusitis' because sinusitis is almost always accompanied by concurrent nasal airway inflammation, and typically, rhinitis symptoms precede sinusitis," Sillers says. The experts agreed no single causative factor fully explains or accounts for the pathological manifestations and clinical differences in rhinosinusitis. However, they did note that chronic rhinosinusitis has a significant inflammatory component that may be caused by persistent infection, including osteitis, allergy or immune disorders, upper airway anatomy issues, aspirin sensitivity, and fungi that may lead to inflammation.
Chronic Condition
The panel also found a lack of clinical trials focusing on chronic rhinosinusitis left physicians without evidence-based guidelines to diagnose and treat the condition.
"One of the greatest challenges for physicians treating rhinosinusitis is determining if the condition is acute or chronic," Sillers emphasizes. "If symptoms resolve completely between brief episodes, the condition is acute, but if a patient complains of recurrent episodes that have not responded to standard treatment, an underlying allergy or anatomic problem may exist," he says.
Chronic rhinosinusitis is an unrelenting disorder lasting longer than 12 weeks, with subgroups of patients with or without polyps or asthma. "The most severe rhinosinusitis inflammation is seen with chronic rhinosinusitis with polyps, asthma, and aspirin sensitivity. These patients are extremely difficult to treat and may require lifelong care, including aggressive medical therapy or surgery," he says. "Because nasal polyps frequently recur, we perform close follow up at 3-month intervals with nasal endoscopy."
Anterior rhinoscopy may determine pathology in the sinonasal passages, but is best performed after use of topical decongestants and may not allow examination beyond the anterior portion of the nasal cavity. Nasal endoscopy helps diagnose erythema, edema, polyps or polypoid swelling, crusting, eosinophilic mucin, and pus deep in the nasal cavity. Although nasal endoscopy is well tolerated, Sillers notes, imaging is strongly encouraged for patients with persistent sinus disease and required for those undergoing endoscopic sinus surgery.
One of the most effective tools in diagnosing rhinosinusitis is a computed tomography (CT) scan, considered the "gold standard" in imaging techniques. "Plain films of the sinuses have poor sensitivity and specificity, but CT scans are relatively inexpensive, help define sinus anatomy prior to surgery, and also help diagnose and manage recurrent or chronic sinusitis. The images show inflammatory changes, as well as anatomic problems, such as enlarged turbinates or a deviated nasal septum," Sillers says.
Fungal Findings
Antibiotics may be effective when bacteria are
present along with worsening inflammation, but
in some cases, it is unclear whether bacteria are causative or associative.
|
Some research, notably a September 1999 study in Mayo Clinic Proceedings, suggests fungus may underlie chronic rhinosinusitis, but Sillers cautions against treating the condition with antifungals, which can be expensive, potentially hepatotoxic, and generally ineffective in treating inflammation initiated outside the mucous membranes.
Although some cases of topical or irrigated amphotericin B have been studied, the approach has not been tested for safety or efficacy in large-scale trials. "In the Mayo study, researchers found fungal growth in the sinus washings of 96% of patients with chronic sinusitis and identified eosinophiles that actively released protein into the mucous, attacking the fungi and irritating the lining of the sinuses, which they suggested potentiate bacterial growth.
"However, the normal controls had almost the same amount of fungus in their sinuses," Sillers points out. "Fungus has been clearly associated with sinusitis, but evidence defining its role as a causative agent is lacking."
Treatment Options
Fortunately, therapeutic options for chronic rhinosinusitis have expanded along with increased diagnoses. Corticosteroid nasal sprays significantly reduce inflammatory response in nasal passages and airways. Newer leukotriene antagonists, such as montelukast (Singulair) and zafirlukast (Accolate), were originally introduced as anti-inflammatory asthma medications, but montelukast also was approved by the Food and Drug Administration in 2003 for treating allergic rhinitis symptoms. The drugs are unique because they come in pill form rather than as a nebulizer, are effective within a few days, are not associated with somnolence, can be combined with other asthma and allergy medications, and have minimal side effects. Montelukast is approved for adults and children aged 2 years and older and may be prescribed for children as chewable tablets or oral granules.
Antibiotics, With Caution
Although antibiotics are often overprescribed for rhinosinusitis, they may be warranted in specific cases. "Antibiotics may be effective when bacteria are present along with worsening inflammation, but in some cases, it is unclear whether bacteria are causative or associative," Sillers says.
Once an ideal customized therapeutic approach has been identified for treating chronic rhinosinusitis, Sillers advises patients to continue uninterrupted medical therapy for 3 to 6 weeks then return for follow up and evaluation of physical findings.
In addition to conventional CT scans, UAB otolaryngologists have used computer-aided transnasal endoscopic surgical techniques for patients with medically refractory rhinosinusitis for nearly a decade. The approach correlates real-time endoscopic images with coronal, axial, and sagittal CT scans, allowing detailed imaging of underlying conditions and anatomy, which translates to less invasive and more precise surgeries.
Although inflammation is one of the most common features of chronic rhinosinusitis, the panel noted that differential diagnoses may include over- or underactivity of autonomic nerve pathways, abnormalities in leukotriene production or responsiveness, nociceptive dysfunction, or local irritation caused by gastroesophogeal reflux. Aspirin-associated respiratory disease, defects in mucociliary clearance, and antibody defiency syndromes also predispose to rhinosinusitis.
"There are numerous potential culprits for causing sinus pain and congestion," Sillers says. "Garnering a detailed history, including allergy and asthma issues, avoiding unnecessary medications, and customizing a medical approach based upon the comprehensive clinical picture is key to relieving symptoms of chronic rhinosinusitis sufferers."
For more information
Dr. Michael Sillers
1.800.UAB.MIST
mist@uabmc.edu
Published in UAB Insight, Summer 2005