You've very likely had such an infection. And if, like 25 million other Americans, you went to a U.S. doctor, there's a 90% chance you got a prescription for antibiotics.
You very likely had some side effects from that antibiotic. But it's extremely unlikely the antibiotics you took were much help, according to a study by Ian G. Williamson, MD, senior lecturer at the University of Southampton, England.
"We are confident that if there is an effect of antibiotics on acute sinus infections, it is not very big -- certainly not as big as people have been led to believe," Williamson tells WebMD.
Williamson and colleagues studied 240 patients ages 16 and older whose symptoms suggested that they had a sinus infection caused by bacteria. Viruses also cause sinus infections, but antibiotics do not help viral infections.
Study patients received antibiotic treatment with amoxicillin, an antibiotic often used for bacterial sinus infections, with or without nasal steroid sprays. A fourth of the patients received no treatment at all, but just got inactive placebo pills and placebo sprays.
Ten days later, patients who got no active treatment were just as likely to be cured as those treated with antibiotics. Steroid nasal sprays made little difference, although they seemed to help people with very mild nasal congestion and seemed to make things a little worse for those with very intense nasal congestion.
Williamson says the study does not definitively rule out some small effect of antibiotics. But that effect would be very small.
"Over a three-week illness -- when your symptoms are not so bad -- would the side effects from a long course of antibiotics be worth a day's less illness? Overall we think antibiotics have a pretty small effect, if there is one there at all," Williamson says.
A decade ago, a carefully controlled study by Norwegian sinusitis expert Morten Lindbaeck, MD, PhD, at the University of Oslo showed that antibiotics had a detectable effect on bacterial sinus infections -- but that the effect is quite modest.
"Even in these very strict cases with a large probability that patients had really tough bacterial infections, more than half of patients were healthy by 10 days," Lindbaeck tells WebMD. "Even if you have a real bacterial infection, most of the time you get well without antibiotics."
What about people who don't get better? That remains a question.
"If they come to me and say, 'I have been sick for seven days and feel very bad and have a fever,' I start antibiotics right away. But that is the few," Lindbaek says. "The large majority of patients with sinus infections are not very sick. They have pain, they are stuffy, they don't feel well enough to go to work, but they are not very ill."
What's wrong with just giving patients antibiotics? Williamson and Lindbaek both note that bacteria are becoming more and more resistant to antibiotic drugs. And antibiotics that are not effective spur the growth of drug-resistant bugs.
Lindbaek says that more cautious prescribing policies among Norwegian doctors is one reason Norway has one-tenth as many important drug-resistant bacteria as does the U.S.
And Williamson says patients and doctors should think about the future.
"It is a green issue," he suggests. "Maybe we will get away with overusing antibiotics, but will our kids get away with it? We should use antibiotics wisely. It is a resource we don't want to use up."
Williamson and colleagues report their findings in the Dec. 5 issue of The Journal of the American Medical Association. An editorial by Lindbaek appears in the same issue.