Acute bacterial rhinosinusitis (ABRS) is one of the most common conditions seen in primary care. The National Institute of Allergy and Immunology estimates that 37 million Americans are affected by sinusitis every year; each year the CDC receives nearly 32 million reports of chronic sinusitis.1 Despite the prevalence of ABRS, many primary-care clinicians are still uncertain about diagnosing and managing the condition. A recent study has revealed excessive and inappropriate prescribing of antibiotics for upper respiratory infections (URIs) of viral etiology.2
Changes in bacterial resistance and the approval of additional antibiotic agents (e.g., high-dose amoxicillin/clavulanate and cefdinir) have prompted changes to existing ABRS treatment guidelines. In 2004, comprehensive diagnostic and management guidelines were published by the Sinus and Allergy Health Partnership (SAHP).3 The guidelines grade the efficacy of various antibiotics in treating ABRS, taking into account spontaneous resolution and resistance rates, symptom severity, and recent antibiotic use by the patient.3
Diagnosing ABRS
Diagnosis in primary care can be challenging. None of the signs or symptoms associated with the disease is both sensitive and specific.4 Predisposing conditions include allergy, trauma, dental infection, or other factors that lead to inflammation of the nose and paranasal passages,3 but most cases of ABRS are preceded by a viral URI, and there is wide overlap between the symptoms of the two conditions. ABRS is typically accompanied by some or all of the following signs and symptoms: rhinorrhea, hyposmia/anosmia, facial pain/pressure, ear fullness/pressure, fever, sore throat, myalgia, fatigue, nasal obstruction/congestion, postnasal drip or purulence, maxillary dental pain, and headache.3
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Because the symptoms lack sensitivity and specificity, SAHP guidelines suggest that diagnosis should also take into account the duration of symptoms and their severity. Diagnosis can generally be made in patients with symptoms of a viral URI that have not improved after 10 days or that worsen after five to seven days and are accompanied by some or all of the signs and symptoms.3
Differentiating viral from bacterial sinusitis may be difficult on the basis of clinical grounds alone. Although most cases of viral sinusitis will resolve without the need for antibiotics, ABRS, if untreated, can have serious consequences. Without prompt treatment, the infection can spread and infect the orbital area or intracranial structures, resulting in periorbital or orbital cellulitis, subperiosteal abscess, brain abscess, and meningitis.3,5,6
Whether and when to initiate antimicrobial therapy for patients with signs and symptoms of ABRS, therefore, requires careful consideration. In general, viral sinusitis will usually resolve without treatment within 7-10 days. If symptoms persist for more than 10 days or worsen after five to seven days, ABRS can more readily be diagnosed and the appropriate treatment implemented.
Managing ABRS
Once ABRS has been diagnosed and a decision to treat with antibiotics has been made, which is the most appropriate agent to prescribe? The three most common causative pathogens are Streptococcus pneumoniae, Hemophilus influenzae, and Moraxella catarrhalis. The exact bacterial etiology, however, can only be determined by sinus aspiration, an invasive procedure that is not practical in the primary-care setting. Treatment must, therefore, be empirical.
The choice of which antibiotic to use is initially based on disease severity and whether or not the patient has received antibiotics within the past four to six weeks. The SAHP guidelines are designed for the treatment of patients with mild or moderate ABRS; severe infections are not addressed.
The patient with mild ABRS and no recent antibiotic use: Management of this unusual type of sinusitis patient is illustrated in “Case study 1.” First-line therapies in patients with mild ABRS and without antibiotic use in the past four to six weeks include amoxicillin/clavulanate, amoxicillin, cefpodoxime proxetil, cefuroxime axetil, and cefdinir.
Failure to respond to antimicrobial therapy after 72 hours (the persistence or worsening of symptoms) should prompt either a switch to an alternative antimicrobial therapy or re-evaluation of the patient.7
The patient with mild disease and previous antibiotic use or with moderate disease: Patients in this category present the greatest treatment challenge because recent antibiotic exposure increases the risk that the patient may be carrying or be infected with resistant bacteria. Antimicrobial therapy should be based on the patient’s history of recent antibiotic use. First-line therapies in patients with mild ABRS who have used an antibiotic in the past four to six weeks or those with moderate disease include amoxicillin/clavulanate, respiratory fluoroquinolones, and ceftriaxone.
As with patients who have not used antibiotics, the persistence or worsening of symptoms over the next 72 hours should prompt either a switch to an alternative antimicrobial therapy or re-evaluation of the patient.
The patient with penicillin allergy: In 2001, the American Academy of Pediatrics issued guidelines recommending specific second-generation (cefuroxime and cefpodoxime) and third-generation (cefdinir) cephalosporin antibiotics for the management of ABRS in pediatric patients with non-type 1 penicillin allergies.7 Nevertheless, many clinicians remain reluctant to prescribe such agents, as rates of cross-sensitivity to cephalosporins among patients with penicillin allergy have been cited as 8%-18%.8,9 Recent evidence, however, suggests that although a predictable, immunologic causal link for allergic reactions may occur with early-generation cephalosporins in patients with penicillin allergy, there is no evidence for such reactions with most second- or third-generation agents.10 These agents are therefore suitable for use in patients with mild ABRS who have not received antibiotics within the past four to six weeks and who are allergic to penicillin. “Case study 2” examines such a patient.
Conclusion
The accurate diagnosis of ABRS and the selection of the most appropriate management strategy according to existing guidelines are important to ensure effective treatment and limit the spread of bacterial resistance. If antibiotic therapy is appropriate, it is important that the optimal agent is administered at the optimal dose and for the optimal duration. To ensure this, it is essential that clinicians base their management decisions on current treatment guidelines.
Patient education can also play a role in limiting bacterial resistance. Patients should be informed about the importance of minimizing antibiotic use. However, when treatment with an antibiotic is deemed appropriate, the importance of adhering to antibiotic therapy and finishing the course of medication, even if symptoms improve, should be emphasized.
Dr. Mackey is associate dean for practice and professor of clinical nursing at The University of Texas Health Science Center, School of Nursing, in Houston.
References
1. National Institutes of Health. Sinusitis Fact Sheet.
2. Ladd E. The use of antibiotics for viral upper respiratory tract infections: an analysis of nurse practitioner and physician prescribing practices in ambulatory care, 1997-2001. J Am Acad Nurse Pract. 2005;17:416-424.
3. Executive Summary. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Sinus and Allergy Health Partnership. Otolaryngol Head Neck Surg. 2004;30(Suppl 1):1-45.
4. Gwaltney JM Jr. Management update of acute bacterial rhinosinusitis and the use of cefdinir. Otolaryngol Head Neck Surg. 2002;127(6 Suppl):S24-S29.
5. Hickner JM, Bartlett JG, Besser RE, et al. Principles of appropriate antibiotic use for acute rhinosinusitis in adults: background. Ann Intern Med. 2001;134:498-505.
6. Poole MD, Portugal LG. Treatment of rhinosinusitis in the outpatient setting. Am J Med. 2005;118 Suppl 7A:45S-50S.
7. American Academy of Pediatrics. Subcommittee on Management of Sinusitis and Committee on Quality Improvement. Clinical practice guideline: management of sinusitis. Pediatrics. 2001;108:798-808.
8. Petz LD. Immunologic reactions of humans to cephalosporins. Postgrad Med J. 1971;47(Suppl):64-69.
9. Thoburn R, Johnson JE 3rd, Cluff LE. Studies on the epidemiology of adverse drug reactions. IV. The relationship of cephalothin and penicillin allergy. JAMA. 1966;198:345-348.
10. Pichichero M. Prescribing cephalosporins to penicillin-allergic patients.
