Overview: It is important to differentiate sinusitis from rhinitis & other causes of nasal congestion / discharge, since there are several trials that support the use of antibiotics for more rapid resolution of sinusitis. Likewise, diagnosis by history and physical exam can obviate the need for more expensive and invasive diagnostic testing including sinus aspiration & culture or CT, while also allowing the practitioner objective criteria for the use of antibiotic therapy. Sinusitis is a common complaint in most primary care settings, affecting 33 million Americans, with total costs related to sinusitis estimated conservatively at $6 billion. Furthermore, chronic sinusitis has been shown to significantly reduce quality-of-life in patients suffering with this affliction.¹ Therefore, making an accurate diagnosis and thereby judiciously using antibiotics have important implications on the community-at-large from an epidemiologic perspective, particularly with regards to management of health care costs, as well as to the development of antibiotic resistance.

Diagnosis: Gold standard is sinus aspiration and culture.² Four-view X-rays have a sensitivity of 70% and specificity of 88% (+LR = 5.8, -LR = 0.3); sinus CT, which can be effective in ruling out sinusitis, has a sensitivity of 100% but specificity of only 65% (+LR = 2.9, -LR = 0.0).³ However, the diagnosis is generally made on clinical grounds alone; radiographic evaluation is usually reserved for refractory or severe cases.³ Acute rhinosinusitis is defined as sinus inflammation for < 4 weeks while chronic rhinosinusitis refers to persisting inflammation > 12 weeks or > 4 weeks after initiation of appropriate therapy. The term subacute rhinosinusitis refers to symptoms lasting between 4-12 weeks.⁴

Symptoms that increase the likelihood of sinusitis include the following:^2,4,5

• Fever
• Malaise
• Cough
• Prolonged nasal congestion
• Maxillary toothache
• Purulent nasal secretions
• Failure to respond to decongestants
• Sinus headache
• Hyposmia / anosmia
• Facial pain or pressure (especially when leaning forward)
• Halitosis

Exam findings suggestive of sinusitis inlcude the following:^2,4,5

• Abnormal examination of the nasal mucosa, specifically erythema, edema, septal deviation, polyps (which can cause obstruction and provoke sinusitis), and purulent secretions, specifically from the middle meatus (superior to the inferior turbinate, which is the first rounded structure you usually see upon examination of the nares with a speculum)
• Frontal / maxillary sinus tenderness (see below)
• Ethmoid sinus tenderness, assessed by pinching the bridge of the nose.
• Abnormal transillumination of sinuses. This finding is elicited by placing a strong light source over the infraorbital rim and judging light transmission on both sides through the hard palate; either dull or opaque transillumination (reduced or no light transmission) is considered abnormal. Transillumination is most useful when the sinus is completely opaque and when the exam is performed by a trained otolaryngologist; the test is less helpful when performed by general internists.

No single sign or symptom is very reliable in ruling in or ruling out sinusitis alone. However, using logistic regression analysis, 5 key signs & symptoms were found to be the most helpful predictors of sinusitis, as seen in the table below:²

When 4 or more of these symptoms were present, the LR for sinusitis was 6.4; however, when none of these signs or symptoms were present, the LR was 0.1, effectively "ruling out" sinusitis. Therefore, using these clinical findings in combination can be very helpful in attempting to "rule in" or "rule out" a diagnosis of sinusitis.²

The American Academy of Otolaryngology - Head and Neck Surgery Task Force on Rhinosinusitis have adopted their own criteria for the diagnosis of rhinosinusitis, consisting of major and minor criteria:⁴

Strong history for rhinosinusitis: ³ 2 major factors, 1 major + 2 minor, or nasal purulence on exam.
Include rhinosinusitis in differential: 1 major factor or ³ 2 minor factors.

The data support these recommendations were not clearly defined; however, this illustrates the controversy surrounding the clinical diagnosis of rhinosinusitis.

Other diseases that may be associated with chronic or recurrent sinusitis include hypogammaglobulinemia, selective IgA deficiency, cystic fibrosis, primary ciliary dyskinesia or Kartagener's syndrome, small-vessel vasculitis, and sarcoidosis.¹ Severe sinusitis with pulmonary and renal disease is characteristic of Wegener's granulomatosis. The Samter triad of aspirin sensitivity, asthma, and nasal polyposis is associated with severe sinusitis and brittle asthma.¹

Complications of sinusitis include local osteomyelitis, mucocele, extension into orbit, cavernous sinus, or CNS. Pott's puffy tumor is swelling over the frontal bone representing extension of frontal sinusitis anteriorly into the bone, often associated with fever and headache.^5,6

Treatment: Consists of decongestants such as phenylephrine or oxymetazoline nasal spray (used for < 7 days due to rebound effect), as well as antibiotic therapy. Several trials have shown superiority of antibiotics + decongestants vs. decongestants + placebo:

• One larger RCT published in BMJ (reviewed in ACP Journal Club) of 130 adults with CT-confirmed sinusitis showed significant improvements in both symptoms and CT findings at 10 days in patients taking either amoxicillin or penicillin versus placebo (NNT = 3 & 4 respectively).⁷
• Another Lancet RCT failed to show a significant difference in outcomes in patients with suspected sinusitis treated with amoxicillin vs. placebo at 2 weeks.⁸
• However, it should be noted that the radiographic criteria in the BMJ trial were more stringent than in the latter trial which could have selected for subjects that were more likely to have bacterial sinusitis, therefore leading to a greater effect of antibiotic therapy.^7-9

It is important to note that a significant proportion of patients will improve with decongestants alone (50-80% of patients reported).^5,7,8 However, there is no convincing evidence that decongestants, topical steroids, or mucolytics are superior to placebo.⁹

Length of antibiotic therapy is controversial; one JAMA study reported no difference in outcomes with 3 days vs. 10 days of TMP/SMX for sinusitis.¹⁰ A length of 7-14 days has been recommended by consensus groups.

Finally, choice of antibiotic may not be of critical importance in the treatment of sinusitis, though the antibiotic chosen should be primarily directed toward S. Pneumoniae, Haemophilus species, and Moraxella. Amoxicillin ± clavulanic acid, TMP/SMX, oral cephalosporins, and various macrolides are all commonly used and have been effective in acute sinusitis treatment.^5,6 The largest systematic review, conducted by the Cochrane Collaboration, concluded that penicillin or amoxicillin 500mg TID x 7-14 days should be first-line therapy for sinusitis.⁹ Other agents showed similar efficacy but were not significantly superior to penicillin or amoxicillin.

Surgical intervention is infrequently indicated; indications for referral to ENT include 1) invasive sinusitis into bone or other contiguous structures; 2) multiple recurrences of sinusitis, especially if anatomic obstruction is suspected; 3) failure to respond to standard medical therapy; 4) suspected fungal sinusitis; and 5) severe or refractory sinusitis in an immunocompromised patient.^5,6 Less invasive functional endoscopic sinus surgery has replaced older, open techniques, and is particularly effective in the management of chronic sinusitis; asthma control and quality-of-life may improve with surgical intervention of refractory cases.¹

Fungal sinusitis: Noninvasive fungal sinusitis should be suspected in patients with atopy and chronic intractable sinusitis (despite adequate treatment) and nasal polyposis. Classic triad includes chronic sinusitis (confirmed by radiologic studies); presence of allergic eosinophilic mucin; and fungal elements in mucin by histology or culture. Typically occurs in immunocompetent patients. Fungal culture of saline nasal washings can help in confirming the diagnosis. Endoscopic sinus surgery is indicated to make the diagnosis, as well as to enable drainage and polyp removal. Treatment also consists of oral / topical steroids, irrigation of sinuses with saline or amphotericin, ± allergen immunotherapy.^11,12

Invasive fungal sinusitis is potentially life-threatening and should be suspected in immunocompromised hosts who present with sinusitis, epistaxis, fever, cough, headache, purulent foul-smelling nasal drainage, crusting of nasal mucosa, painless nasal septal ulcers / eschars, and mental status changes (with advanced disease). Dissemination can be rapid without early treatment, and can be fatal within days. Emergency radical surgery for debridement should be performed on patients with consistent clinical signs & symptoms, as well as initiation of antifungal treatment with amphotericin B. Prognosis is poor in those presenting with intracranial involvement.¹¹

^{Reprinted from Reference 6.}

1. Kennedy DW. A 48-year-old man with recurrent sinusitis. JAMA 2000; 283: 2143-50.
2. Williams JW, Simel DL. Does this patient have sinusitis? JAMA 1993; 270: 1242-46.
3. Chodosh J. Acute Sinusitis. In: Black ER et al, eds. Diagnostic Strategies for Common Medical Problems, 2nd ed. Philadelphia: ACP-ASIM; 1999: 293-302.
4. Lanza DC, Kennedy DW. Adult rhinosinusitis defined. Otolaryngol Head Neck Surg 1997; 117 (3 pt 2): S1-S7.
5. Fekete T. Acute sinusitis. In: Up-To-Date, Feb 8, 2000.
6. Slavin RG. Nasal polyps and sinusitis. JAMA 1997; 278: 1849-54.
7. Lindbaek M, Hjortdahl P, Johnsen UL. Randomised, double blind, placebo controlled trial of penicillin V and amoxycillin in treatment of acute sinus infections in adults. BMJ 1996; 313: 325-9.
8. Van Buchem FL, Knottnerus JA, Schrijnemaekers VJJ. Primary care-based placebo-controlled trial of antibiotic treatment in acute maxillary sinusitis. Lancet 1997; 349: 683-7.
9. Williams JW et al. Antibiotics for acute maxillary sinusitis. Cochrane Database of Systematic Reviews. Issue 3, 2000.
10. Williams JW, Holleman DR, Samsa GP, Simel DL. Randomized controlled trial of 3 vs. 10 days of trimethoprim/sulphamethoxazole for acute maxillary sinusitis. JAMA 1995; 273: 1015-21.
11. DeShazo RD, Chapin K, Swain WE. Fungal sinusitis. NEJM 1997; 337: 254-9.
12. Ponikau JU, Sherris DA, Kern EB, Homburger HA, Frigas E, Gaffey TA, Roberts GD. The diagnosis and incidence of allergic fungal sinusitis. Mayo Clin Proc 1999; 74: 877-84.

D. Suh 11/7/00