What are the effects of treatments in people with clinically diagnosed acute sinusitis?

UNKNOWN EFFECTIVENESS

Antibiotics

Two randomized controlled trials (RCTs) found no evidence that amoxicillin reduced or cured symptoms compared with placebo in people with clinically diagnosed acute sinusitis, who had not had radiologic or bacteriologic confirmation of disease. One RCT has found that diarrhea was more common with amoxicillin than with placebo. We found no RCTs examining effects of other antibiotics (amoxicillin–clavulanate, co-trimoxazole, cephalosporins, azithromycin, and erythromycin) compared with placebo or each other.

Antihistamines; Decongestants; Steroids (Topical)

We found no RCTs examining clinical effects of topical or systemic decongestants, topical steroids, or antihistamines in people with clinically diagnosed acute sinusitis.

What are the effects of treatments in people with radiologically or bacteriologically confirmed acute sinusitis?

LIKELY TO BE BENEFICIAL

Cephalosporins and Macrolides (Fewer Adverse Effects than Amoxicillin or Amoxicillin–Clavulanate)

One systematic review in people with radiologically or bacteriologically confirmed acute sinusitis found no significant difference in clinical resolution between amoxicillin or amoxicillin–clavulanate and cephalosporins or macrolides. However, cephalosporins and macrolides caused fewer adverse effects than amoxicillin and amoxicillin–clavulanate. One RCT found no significant difference in clinical improvement or clinical cure between cefaclor (a cephalosporin) and azithromycin (a macrolide).

TRADE-OFF BETWEEN BENEFITS AND HARMS

Amoxicillin and Amoxicillin–Clavulanate (More Adverse Effects than Cephalosporins or Macrolides)

One systematic review identified two RCTs in people with radiologically or bacteriologically confirmed acute maxillary sinusitis, which found that amoxicillin improved early clinical cure rates compared with placebo, but was associated with more frequent adverse effects, mainly gastrointestinal. One systematic review in people with radiologically or bacteriologically confirmed acute sinusitis found no significant difference in clinical resolution between amoxicillin or amoxicillin–clavulanate, and cephalosporins or macrolides. However, amoxicillin and amoxicillin–clavulanate caused more adverse effects.

UNKNOWN EFFECTIVENESS

Different Dosages of Antibiotics

One RCT in people with radiologically or bacteriologically confirmed acute sinusitis found no significant difference in clinical resolution rates or adverse events between two and three daily doses of cefaclor (a cephalosporin).

Antihistamines; Decongestants; Steroids (Topical)

We found no RCTs examining effects of antihistamines, decongestants, or topical steroids in people with radiologically or bacteriologically confirmed acute sinusitis.

UNLIKELY TO BE BENEFICIAL

Long-Course Antibiotic Regimens (No More Effective than Short-Course Regimens, and More Adverse Effects)

RCTs in people with confirmed acute sinusitis found no significant difference in clinical resolution rates between a 10-day course and three- to five-day courses of co-trimoxazole or cefuroxime up to three weeks after treatment. One RCT found that adverse effects, which were mainly gastrointestinal, were more frequent with longer course cefuroxime (a cephalosporin) than with shorter course cefuroxime.

Definition

Acute sinusitis is defined pathologically by transient inflammation of the mucosal lining of the paranasal sinuses lasting less than four weeks. Clinically, it is characterized by nasal congestion, rhinorrhea, facial pain, hyposmia (reduced, not absent, sense of smell), sneezing, and, if more severe, additional malaise and fever. The diagnosis is usually made clinically (on the basis of history and examination, but without radiologic or bacteriologic investigation). Clinically diagnosed acute sinusitis is less likely to be caused by bacterial infection than is acute sinusitis confirmed by radiologic or bacteriologic investigation.¹ In this chapter, we have excluded studies in children, in people with symptoms for more than four weeks (chronic sinusitis), and in people with symptoms following facial trauma. We have made it clear in each section whether we are dealing with clinically diagnosed acute sinusitis or acute sinusitis that has been confirmed by bacteriologic or radiologic investigation, because the effects of treatment may be different in these groups.

Incidence/Prevalence

Each year in Europe, between 1 and 5 percent of adults are diagnosed with acute sinusitis by their general practitioner.² Extrapolated to the British population, this is estimated to cause 6 million restricted working days per year.^3,4 Most people with acute sinusitis are assessed and treated in a primary care setting. The prevalence varies according to whether diagnosis is made on clinical grounds or on the basis of radiologic or bacteriologic investigation.

Etiology/Risk Factors

One systematic review (search date 1998) reported that about 50 percent of people with a clinical diagnosis of acute sinusitis have bacterial sinus infection.¹ The usual pathogens in acute bacterial sinusitis are Streptococcus pneumoniae and Haemophilus influenzae, with occasional infection with Moraxella catarrhalis. Preceding viral upper respiratory tract infection is often the trigger for acute bacterial sinusitis,⁵ with about 0.5 percent of common colds becoming complicated by the development of acute sinusitis.⁶

Prognosis

One meta-analysis of RCTs found that up to two thirds of people with acute sinusitis had spontaneous resolution of symptoms without active treatment.⁷ One nonsystematic review reported that people with acute sinusitis are at risk of chronic sinusitis and irreversible damage to the normal mucociliary mucosal surface.⁸ One further nonsystematic review reported rare life-threatening complications, such as orbital cellulitis and meningitis following acute sinusitis.⁹ However, we found no reliable data to quantify these risks.