<P> Some cases may be prevented by hand washing, avoiding smoking, and immunization . Pain killers such as naproxen, nasal steroids, and nasal irrigation may be used to help with symptoms . Recommended initial treatment for ARS is watchful waiting . If symptoms do not improve in 7--10 days or get worse, then an antibiotic may be used or changed . In those in whom antibiotics are used, either amoxicillin or amoxicillin / clavulanate is recommended first line . Surgery may occasionally be used in people with chronic disease . </P> <P> Sinusitis is a common condition . It affects between about 10% and 30% of people each year in the United States and Europe . Women are more often affected than men . Chronic sinusitis affects approximately 12.5% of people . Treatment of sinusitis in the United States results in more than 11 billion USD in costs . The unnecessary and ineffective treatment of viral sinusitis with antibiotics is common . </P> <P> Sinusitis (or rhinosinusitis) is defined as an inflammation of the mucous membrane that lines the paranasal sinuses and is classified chronologically into several categories: </P> <Ul> <Li> Acute rhinosinusitis--A new infection that may last up to four weeks and can be subdivided symptomatically into severe and non-severe . Some use definitions up to 12 weeks . </Li> <Li> Recurrent acute rhinosinusitis--Four or more full episodes of acute sinusitis that occur within one year </Li> <Li> Subacute rhinosinusitis--An infection that lasts between four and 12 weeks, and represents a transition between acute and chronic infection </Li> <Li> Chronic rhinosinusitis--When the signs and symptoms last for more than 12 weeks . </Li> <Li> Acute exacerbation of chronic rhinosinusitis--When the signs and symptoms of chronic rhinosinusitis exacerbate, but return to baseline after treatment </Li> </Ul>

Inflammation of the mucous membranes of the sinuses is called