Causes and Risk Factors - Sinusitis is often caused by a viral infection, such as the common cold. - Underlying conditions like allergies or structural problems in the nose can increase the risk of sinusitis. - People with lesser immunity against bacteria by birth are more prone to sinusitis. - Recurrent episodes are more likely in individuals with asthma, cystic fibrosis, and poor immune function. - Most cases of sinusitis are caused by a viral infection, not bacteria. - Acute sinusitis is usually caused by viral infections, such as rhinoviruses, coronaviruses, and influenza viruses. - Bacterial infections can also cause acute sinusitis, with Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis being common culprits. - Fungal invasion can lead to acute sinusitis, especially in individuals with diabetes or immune deficiencies. - Chronic sinusitis can be caused by various diseases, including anatomic derangements, allergic rhinitis, asthma, cystic fibrosis, and dental infections. - Smoking and secondhand smoke are associated with chronic sinusitis.

Signs and Symptoms - Common symptoms of sinusitis 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 frequent coughing. - Acute sinusitis may be accompanied by a green nasal discharge that may contain pus or blood. - Chronic sinusitis can lead to nasal congestion, facial pain, headache, night-time coughing, and an increase in asthma symptoms. - Anosmia, the loss of the sense of smell, is often associated with chronic sinusitis.

Diagnosis - In early stages, an ENT doctor can confirm sinusitis using nasal endoscopy. - Diagnostic imaging is usually not needed in the acute stage unless complications are suspected. - In chronic cases, confirmatory testing is recommended through direct visualization or computed tomography. - The unnecessary and ineffective treatment of viral sinusitis with antibiotics is common. - Sinusitis is classified into several categories based on the duration of symptoms, including acute, recurrent acute, subacute, chronic, and acute exacerbation of chronic sinusitis. - Roughly 90% of adults have had sinusitis at some point in their lives. - Bacterial and viral sinusitis can be distinguished through watchful waiting. - Diagnostic methods include noting local tenderness and dull pain, CT and nuclear isotope scanning, and microbial culture. - Chronic sinusitis can be part of a spectrum of diseases affecting the respiratory tract and is often linked to asthma.

Treatment - Initial treatment for acute sinusitis is watchful waiting. - If symptoms do not improve in 7-10 days or get worse, an antibiotic may be used. - Pain killers such as naproxen, nasal steroids, and nasal irrigation can help with symptoms. - Amoxicillin or amoxicillin/clavulanate is recommended as the first-line antibiotic treatment. - Surgery may be used in people with chronic sinusitis or those who do not respond to medications. - Treatment for sinusitis includes surgical drainage and administration of antimicrobial therapy. - Surgical debridement is rarely required after an extended course of parenteral antimicrobial therapy. - Chronic sinusitis is managed by controlling inflammation and reducing the incidence of infections. - Medications are the first line of treatment, but surgery may be necessary if medications are ineffective. - Antifungal treatments have had mixed results in treating chronic sinusitis associated with fungi.

Complications and Prognosis - Complications of sinusitis are rare but can be life-threatening. - Infection of the brain is the most dangerous complication, particularly in the frontal and sphenoid sinuses. - Sinus infection can spread to the orbit, causing periorbital cellulitis, abscesses, and orbital cellulitis. - Sinusitis may extend to the central nervous system, causing cavernous sinus thrombosis, meningitis, and brain abscesses. - Other complications include sinobronchitis, maxillary osteomyelitis, and frontal bone osteomyelitis. - Odontogenic sinusitis (ODS) can occur when an infection or complication of a dentistry procedure involves the maxillary sinus. - Sinus infections can spread to other sinuses, including the ethmoid, frontal, and sphenoid sinus. - Infections may involve the orbit, causing orbital cellulitis and potentially leading to blindness. - Sinus infections can also result in central nervous system complications such as meningitis, brain abscess, and cavernous sinus thrombosis. - Ethmoid sinusitis can lead to infection of the eye socket, resulting in the loss of sight and accompanied by fever and severe illness. - 46% of sinusitis cases without antibiotics are cured after one week. - 64% of sinusitis cases without antibiotics are cured after two weeks. - 24 to 31 million sinusitis cases occur annually in the United States. - Chronic sinusitis affects approximately 12.5% of people.