Sinus infections, and the unpleasant pain and pressure they can cause, are a rite of spring, and of summer. But recent research indicates that antibiotics, while a popular fix for some acute sinus ailments, are sometimes ordered for nasal infections on which they’ll have no effect.

A study published in the Archives of Otolaryngology-Head and Neck Surgery found antibiotics are prescribed for approximately eighty-two percent of acute sinus infections and nearly seventy percent of chronic sinus infections. That’s despite the fact that viruses are by far the most frequent cause of this condition. Antibiotics, while powerful against a bacterial onslaught, are ineffective at treating viral infections.

In 2002, inflammation of the sinus cavities accounted for twenty-one percent of all antibiotic prescriptions for adults and nine percent of those for children. An infection is considered acute when symptoms last up to four weeks, and chronic when they persist for twelve weeks or more. Acute rhinosinusitis [rye-no-sinus-eye-tiss] is usually thought to be caused by infectious agents, while allergies, facial anatomy and hormonal changes may contribute to chronic cases.

Researchers noted that physicians may believe antibiotics are effective because patients improved while taking them, while in fact the symptoms may have cleared up without treatment. Doctors say two-thirds of patients with sinus symptoms expect or receive an antibiotic, and as many as one-fifth of antibiotic prescriptions for adults are written for a drug to treat rhinosinusitis. Experts urge caution against overuse of antibiotics, as drug resistance is a growing problem in medicine.