Sinusitis, also known as a sinus infection or rhinosinusitis, is inflammation of the mucous membrane that lines the sinuses resulting in symptoms. Common symptoms include thick nasal mucus, a plugged nose, and facial pain. Other signs and symptoms may include fever, headaches, a poor sense of smell, sore throat, and a cough. The cough is often worse at night. Serious complications are rare. It is defined as acute sinusitis if it lasts less than 4 weeks, and as chronic sinusitis if it lasts for more than 12 weeks.
Sinusitis can be caused by infection, allergies, air pollution, or structural problems in the nose. Most cases are caused by a viral infection. A bacterial infection may be present if symptoms last more than ten days or if a person worsens after starting to improve. Recurrent episodes are more likely in persons with asthma, cystic fibrosis, and poor immune function. X-rays are not usually needed unless complications are suspected. In chronic cases confirmatory testing is recommended by either direct visualization or computed tomography.
Sinusitis can be caused by infection, allergies, air pollution, or structural problems in the nose. Most cases are caused by a viral infection. A bacterial infection may be present if symptoms last more than ten days or if a person worsens after starting to improve. Recurrent episodes are more likely in persons with asthma, cystic fibrosis, and poor immune function. X-rays are not usually needed unless complications are suspected. In chronic cases confirmatory testing is recommended by either direct visualization or computed tomography.
Classification
Sinusitis (or rhinosinusitis) is defined as an inflammation of the mucous membrane that lines the paranasal sinuses and is classified chronologically into several categories:
Roughly 90 percent of adults have had sinusitis at some point in their life.
- Acute sinusitis – 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.
- Recurrent acute sinusitis – Four or more full episodes of acute sinusitis that occur within one year
- Subacute sinusitis – An infection that lasts between four and 12 weeks, and represents a transition between acute and chronic infection
- Chronic sinusitis – When the signs and symptoms last for more than 12 weeks.
- Acute exacerbation of chronic sinusitis – When the signs and symptoms of chronic sinusitis exacerbate, but return to baseline after treatment
Roughly 90 percent of adults have had sinusitis at some point in their life.