Abstract: We included 15 trials involving 3057 participants. Of the 15 included trials, 10 appeared in our 2012 review, and five (631 participants) are legacy trials from merging two reviews. No new studies were included from searches for this update. Overall, risk of bias was low. Without antibiotics, 46% of participants with rhinosinusitis, whether or not confirmed by radiography, were cured after 1 week and 64% after 14 days. Antibiotics can shorten time to cure, but only 5 to 11 more people per 100 will be cured faster if they receive antibiotics instead of placebo or no treatment: clinical diagnosis (odds ratio (OR) 1.25, 95% confidence interval (CI) 1.02 to 1.54; number needed to treat for an additional beneficial outcome (NNTB) 19, 95% CI 10 to 205; I² = 0%; 8 trials; high-quality evidence) and diagnosis confirmed by radiography (OR 1.57, 95% CI 1.03 to 2.39; NNTB 10, 95% CI 5 to 136; I² = 0%; 3 trials; moderate-quality evidence). Cure rates with antibiotics were higher when a fluid level or total opacification in any sinus was found on computed tomography (OR 4.89, 95% CI 1.75 to 13.72; NNTB 4, 95% CI 2 to 15; 1 trial; moderate-quality evidence). Purulent secretion resolved faster with antibiotics (OR 1.58, 95% CI 1.13 to 2.22; NNTB 10, 95% CI 6 to 35; I² = 0%; 3 trials; high-quality evidence). However, 13 more people experienced side effects with antibiotics compared to placebo or no treatment (OR 2.21, 95% CI 1.74 to 2.82; number needed to treat for an additional harmful outcome (NNTH) 8, 95% CI 6 to 12; I² = 16%; 10 trials; high-quality evidence). Five fewer people per 100 will experience clinical failure if they receive antibiotics instead of placebo or no treatment (Peto OR 0.48, 95% CI 0.36 to 0.63; NNTH 19, 95% CI 15 to 27; I² = 21%; 12 trials; high-quality evidence). A disease-related complication (brain abscess) occurred in one participant (of 3057) one week after receiving open antibiotic therapy (clinical failure, control group). The potential benefit of antibiotics to treat acute rhinosinusitis diagnosed either clinically (low risk of bias, high-quality evidence) or confirmed by imaging (low to unclear risk of bias, moderate-quality evidence) is marginal and needs to be seen in the context of the risk of adverse effects. Considering antibiotic resistance, and the very low incidence of serious complications, we conclude there is no place for antibiotics for people with uncomplicated acute rhinosinusitis. We could not draw conclusions about children, people with suppressed immune systems, and those with severe sinusitis, because these populations were not included in the available trials.

Plain-language summary: We included 15 studies in which adults with short-duration sinus infection, whether or not confirmed by imaging, randomly received antibiotics, or a dummy drug or no treatment, in ambulatory care settings. The studies included a total of 3057 adults whose average age was 36 years; about 60% were female. Participants were followed until they were cured. Trial duration ranged from 8 to 28 days. Seven studies received financial support from government or academic institutions; six received grants from the pharmaceutical industry; and five did not state sources of support. Without antibiotics, almost half of all participants were cured after one week, and two out of three were cured after 14 days. Five (diagnosis based on symptoms described to a doctor) to 11 (diagnosis confirmed by x-ray) more people per 100 were cured faster with antibiotics. A computed tomography (CT) scan could better predict who would benefit from antibiotics, but routine use would cause health problems related to radiation exposure. Ten more people per 100 were relieved faster of thick, yellow discharge from the nose with antibiotics compared to a dummy drug or no treatment. Thirteen more people per 100 experienced side effects (mostly concerning stomach or intestines) with antibiotics compared to a dummy drug or no treatment. Compared with people who initially started antibiotics, five more people per 100 in the dummy drug or no treatment group had to start antibiotics because their condition worsened. Serious complications (e.g. brain abscess) were rare. We found that antibiotics are not a first-choice treatment for adults with short-duration sinus infection. We found no evidence relating to adults with severe sinusitis or with reduced immunity, or to children. We found high-quality evidence when the diagnosis was based on symptoms described to a doctor. We downgraded evidence quality to moderate when diagnosis was confirmed by x-ray or CT scan because the number of participants was small, which makes the estimates less reliable.