Vol. 10 •Issue 4 • Page 20
allergy & Asthma
Emerging Rhinosinusitis Strategies
By Daniel L. Hamilos, MD
Concerns about antibiotic overuse and increasing antimicrobial resistance were the major impetus for the Sinus and Allergy Health Partnership to establish new treatment guidelines1 for acute bacterial rhinosinusitis.
The SAHP consisted of a group of experts from the fields of otolaryngology/head and neck surgery, pediatrics, internal medicine, pharmacology and epidemiology, and representatives from the Centers for Disease Control and Prevention, the Food and Drug Administration (FDA) and the pharmaceutical industry. They tackled the challenges of defining the disease and deciding who needs treatment.
DEFINING ABRS
The SAHP report used the consensus definition for rhinosinusitis that an expert panel developed in 1996.2 “Rhinosinusitis” replaced the term “sinusitis” to emphasize the interrelationships between nasal and sinus pathology and to acknowledge the difficulty in separating rhinitis and sinusitis on clinical grounds.
Rhinosinusitis is defined as an inflammatory response involving the mucus membranes of the nasal cavity and paranasal sinuses, fluids within these cavities and/or underlying bone. (See symptoms, page 23.)
This distinction between acute bacterial rhinosinusitis (ABRS) and viral upper respiratory infections (viral URIs) is highly relevant. Viral URIs (i.e., virus-associated common cold) actually represent viral rhino-sinusitis commonly associated with abnormalities on sinus CT scans that may persist up to three weeks after the URI.3
In children, an estimated 10 percent of viral URIs lead to acute bacterial sinusitis, whereas in adults it may be only 0.5 percent to 2.5 percent. Nonetheless, given an annual incidence of one billion cases of VRS in the United States, roughly 20 million cases of VRS are complicated by ABRS annually.1
Patients and physicians have difficulty distinguishing viral URIs from acute bacterial sinusitis. In two recent pediatric studies, between 49 percent and 74 percent of children visiting a physician for a URI were given a prescription for an antibiotic.4,5 The situation is quite similar in Canada, despite public concern over inappropriate use of antibiotics in children with URIs and growing problems with antimicrobial drug resistance.5 One encouraging sign is that at least one study showed the percentage of children receiving an antibiotic for URI has declined modestly in the Boston area over the past few years.6
The SAHP report emphasized the continuum of viral URIs and ABRS. Because most cases of ABRS are preceded by a viral URI, the experts viewed ABRS as an extension of the viral URI. An ABRS diagnosis may be made in either adults or children if symptoms of a viral URI have not improved after 10 days or are worse after five to seven days.1 The SAHP did not regard physical examination findings and sinus transillumination as particularly useful in establishing an ABRS diagnosis.
WHO SHOULD BE TREATED?
Considering the growing concern of antibiotic resistance emergence and that viral rhinosinusitis is at least 20 to 200 times more likely than ABRS,7 the next question is: “Who should be treated?”
In studies of antibiotic treatment of ABRS, 69 percent of patients reported improvement or cure with placebo, but antibiotics reduced significantly the number of treatment failures. Spontaneous resolution rate for pediatric ABRS is an estimated 49.6 percent.1
Most experts agree that excessive use of antibiotics for viral rhino sinusitis may be a contributing factor to the development of antibiotic resistance in Streptococcus pneumoniae and other upper respiratory bacterial pathogens.5,6,8 Widespread consensus maintains that only patients meeting the clinical definition of ABRS should be treated with antibiotics. Therefore, clinicians must consider: “What constitutes judicious use of antibiotics?” and “What is the impact of rising antibiotic resistance on medical therapy?”
ANTIBIOTIC RESISTANCE
Antimicrobial resistance is clearly increasing among the three most common bacterial pathogens implicated in ABRS–Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. At present, roughly 40 percent of H. influenzae and greater than 90 percent of M. catarrhalis are resistant to penicillin due to production of beta-lactamase.1 Penicillin resistance in pneumococci, which is primarily due to alterations in penicillin binding proteins, currently ranges from 28 percent to 44 percent in S. pneumoniae isolates in various regions of the United States.9
The incidence appears to have risen at an alarming rate over the past decade in various parts of the world.10 The prevalence of intermediate (penicillin MIC 0.12 µg/mL to 1.0 µg/mL) and high-level (penicillin MIC greater than or equal to 2.0 µg/mL) penicillin resistance in outpatient isolates of S. pneumoniae was 16.1 percent and 28.6 percent respectively in 1998.11
Data on the prevalence of penicillin-resistant pneumococci in sinusitis are very limited. In a recent study involving cultures of tympanic fluid or sinus aspirates, S. pneumoniae were isolated in 7.8 percent of cultures, and 58 percent of these were resis – tant to penicillin.8 Isolation of penicillin non-susceptible pneumococci (PNSSP) was most commonly seen in patients with recent use of two or more antibiotics.8,10 Other risk factors associated with PNSSP include age less than 5 years and attendance in a day care center.1
Many of these organisms also demonstrate multiple drug resistance.9 As demonstrated by Brook et al.12, beta-lactamase producing bacteria also can emerge during antibiotic treatment during the transition from acute to chronic sinusitis.
The effect of penicillin resistance in pneumococcal infections on treatment outcomes remains controversial except in the area of pneumococcal meningitis.13 Several retrospective studies have failed to show major differences in treatment outcomes in patients infected with PSSP or PNSSP. However, these were mostly hospital-based retrospective studies that were not control-led for treatment differences between groups.
The SAHP report places a heightened awareness on the potential clinical significance of PNSSP on treatment outcomes and the potential for promoting emergence of PNSSP strains by using conventional doses of amoxicillin in patients with moderate disease or prior antibiotic treatment.
TREATMENT
Goals of ABRS antibiotic treatment, as articulated in the SAHP document, are:
• to return the sinuses back to health
• to prevent severe complications such as meningitis and brain abscess
• to decrease the development of chronic disease.
In routine practice, antibio-tic selection for ABRS remains empiric based upon the most probable infectious organisms.14
In addition, the SAHP guidelines list three important factors for antibiotic treatment of ABRS:
• Severity of illness (mild and moderate categories)
• Prior antibiotic use in the previous four to six weeks
• Escalating doses of penicillin-type drugs in circumstances where the prevalence of penicillin-resistant pneumococci is greater.1
Examples of symptoms that justify ABRS as moderate in severity include low-grade fever and unilateral maxillary or frontal tenderness that worsens with bending over.
The guidelines also include provisions for “switch” therapy based on treatment failure, defined as failure to improve at greater than or equal to 72 hours of therapy initiation. Recommendations for adults and children are very similar, but the SAHP acknowledged that it may be more difficult to differentiate a viral URI from ABRS in children.
For initial treatment of adults with mild disease who have not received antibiotics in the previous four to six weeks, clinicians recommend amoxicillin/clavulanate, amoxicillin (1.5 g/day to 3.5 g/day), cefpodoxime proxetil or ce-furoxime axetil. They recommend alternative antibiotics for patients allergic to these choices.
For initial therapy of adults with mild disease who have received antibiotics in the previous four to six weeks or who have moderate disease and have not received antibiotics in the previous four to six weeks, the antibiotic choices are amoxicillin/clavulanate, amoxicillin (3 g/day to 3.5 g/day), cefpodoxime proxetil or cefuroxime axetil.
When clinicians prescribe amoxicillin/clavulanate in areas with a high prevalence of PNSSP or as “switch” therapy, a total of 3 g/day to 3.5 g/day of the amoxicillin component is recommended, although this is not currently FDA approved.
References
1. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Executive Summary. Sinus and Allergy Health Partnership. Otolaryngol Head Neck Surg. 2000;123(1 Pt. 2):1-31.
2. Lanza DC, Kennedy DW. Adult rhinosinusitis defined. Otolaryngol Head Neck Surg. 1997 Sep;117(3 Pt 2):S1-7.
3. Gwaltney JM, Phillips CD, Miller RD, Riker DK. Computed tomographic study of the common cold. N Engl J Med. 1994;330(1): 25-30.
4. Watson RL, Dowell SF, Jayaraman M, Keyserling H, Kolczak M, Schwartz B. Antimicrobial use for pediatric upper respiratory infections: reported practice, actual practice, and parent beliefs. Pediatrics. 1999 Dec;104(6):1251-7.
5. Wang EE, Einarson TR, Kellner JD, Conly JM. Antibiotic prescribing for Canadian preschool children: evidence of overprescribing for viral respiratory infections. Clin Infect Dis. 1999 Jul;29(1):155-60.
6. Finkelstein JA, Metlay JP, Davis RL, Rifas-Shiman SL, Dowell SF, Platt R. Antimicrobial use in defined populations of infants and young children. Arch Pediatr Adolesc Med. 2000 Apr;154(4):395-400.
7. O’Brien KL, Dowell SF, Schwartz B, Marcy SM, Phillips WR, Gerber MA. Acute sinusitis– principles of judicious use of antimicrobial agents. Pediatrics. 1998;101 (Suppl):174-7.
8. Shapiro NL, Pransky SM, Martin M, Bradley JS. Documenta-tion of the prevalence of penicillin-resistant Streptococcus pneumoniae isolated from the middle ear and sinus fluid of children undergoing tympanocentesis orsinus lavage. Ann Otol Rhinol Laryngol. 1999 Jul;108(7 Pt 1):629-33.
9. Thornsberry C, Jones ME, Hickey ML, Mauriz Y, Kahn J, Sahm DF. Resistance surveillance of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis isolated in the United States, 1997-1998. J Antimicrob Chemother. 1999;44(6): 749-59.
10. Lu CY, Lee PI, Hsueh PR, Chang SC, Chiu TF, Lin HC, et al. Penicillin-nonsusceptible Streptcoccus pneumoniae infections in children. J Microbiol Immunol Infect. 1999 Sep;32(3):179-86.
11. Jacobs M, Bajaksouzian S, Lin G, et al. Susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to oral agents: results of a 1998 US outpatient surveillance study. ICAAC. 1999; Abstract C-61.
12. Brook I, Frazier EH, Foote PA. Microbiology of the transition from acute to chronic maxillary sinusitis. J Med Microbiol. 1996;45(5):372-5.
13. Pallares R, Viladrich PF, Linares J, Cabellos C, Gudiol F. Impact of antibiotic resistance on chemotherapy for pneumococcal infections. Microb Drug Resist. 1998 Winter;4(4):339-47.
14. Low DE, Desrosiers M, McSherry J, Garber G, Williams JW, Remy H, et al. A practical guide for the diagnosis and treatment of acute sinusitis. CMAJ. 1997 Mar 15;156 (Suppl 6):1-14.
Dr. Hamilos is associate professor of medicine, Washington University School of Medicine, St. Louis.
Managing Sinusitis Symptoms
Patients need to understand that they can’t rely solely on antibiotics to treat rhinosinusitis because the mucus needs to be drained from the sinuses, explains Wellington S. Tichenor, MD, assistant professor of clinical medicine at New York Medical College, and allergist at a private practice in Manhattan.
Other treatment options that can help alleviate symptoms and reduce pain include:
• Taking mucus thinner medications, drinking lots of water and inhaling steam will help thin mucus. Decongestants open the ostia through which the mucus drains.
• Steroid nasal sprays can reduce inflammation, and other anti- inflammatory medications such as aspirin and ibuprofen can help relieve pain in patients who are not allergic to them.
• Irrigation systems can help drain mucus in post-surgery patients and rhinosinusitis sufferers who have not undergone surgery. Make sure patients know that they need to use an irrigator tip that is adapted for the nose, Dr. Tichenor advises. Antifungal irrigations can help treat fungal sinusitis infections, but the antifungal agents often have to be refrigerated and protected from light, sometimes making their storage inconvenient.
• Saline sprays also wash out mucus and moisturize the nose.
• Humidifiers moisturize the nasal passages. Dr. Tichenor typically suggests patients keep the humidity level between 40 percent and 50 percent; higher humidification levels promote the growth of mold and dust mites. Many patients prefer a hot mist, but he recommends using cool mist if there will be young children around who risk getting burned.
• Mechanical devices can help patients with obstruction breathe better. Some mechanical devices work like an elastic bandage across the nose and use an embedded spring to keep the nose open. Others look like new-fangled paper clips that are inserted in the nose.
• Anecdotal reports from patients have suggested that herbal supplements such as Echinacea, bromelain and goldenseal may be helpful, but there isn’t much medical research to support this.
• Patients who have nasal polyps and rhinosinusitis may respond to oral or nasal spray anti-leukotriene agents, according to some reports.
• It’s critical that patients be evaluated for outside agents that may exacerbate rhinosinusitis. Smoke causes paralysis of the cilia and must be avoided to treat sinusitis adequately. Alcohol can cause dehydration, forgetfulness concerning medications, and in some cases allergy.
“When patients don’t respond well to medical treatment, an evaluation with nasal endoscopy and CT scan is the next step,” Dr. Tichenor says. Then he recommends patients have a surgical consultation. Some newer techniques use image-guided surgery, which allows the surgeon to correlate where he’s operating in the sinuses with the CT scan.
For more information see Dr. Tichenor’s Web site at www.sinuses.com.
–By Jennifer Gillespie, assistant editor of ADVANCE.
Symptoms of rhinosinusitis most commonly include:
• nasal discharge
• nasal congestion
• facial pressure and/or pain
• postnasal drip
• alteration in the sense of smell (hyposmia/anosmia)
• fever
• cough
• fatigue
• dental pain
• otologic symptoms (e.g., ear fullness and clicking)
• halitosis
• pharyngitis
• headache.
Contrary to popular belief, a change in the color or consistency of nasal discharge is not a specific sign of a bacterial infection.1
REFERENCE
1. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Executive Summary. Sinus and Allergy Health Partnership. Otolaryngol Head Neck Surg. 2000;123(1 Pt. 2):1-31.
–Daniel L. Hamilos, MD
