Sinusitis

Acute sinusitis in immunocompetent patients in the community is almost always viral (eg, rhinovirus, influenza, parainfluenza). A small percentage develop secondary bacterial infection with streptococci, pneumococci, Haemophilus influenzae, Moraxella catarrhalis, or staphylococci. Occasionally, a periapical dental abscess of a maxillary tooth spreads to the overlying sinus. Hospital-acquired acute infections are more often bacterial, typically involving Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Enterobacter. Immunocompromised patients may have acute invasive fungal sinusitis (see Sinusitis in Immunocompromised Patients Invasive Sinusitis in Immunocompromised Patients Sinusitis is inflammation of the paranasal sinuses due to viral, bacterial, or fungal infections or allergic reactions. Symptoms include nasal obstruction and congestion, purulent rhinorrhea... read more ).

Chronic sinusitis involves many factors that combine to create chronic inflammation. Chronic allergies, structural abnormalities (eg, nasal polyps), environmental irritants (eg, airborne pollution, tobacco smoke), mucociliary dysfunction, and other factors interact with infectious organisms to cause chronic sinusitis. The organisms are commonly bacterial (possibly as part of a biofilm on the mucosal surface) but may be fungal. Many bacteria have been implicated, including gram-negative bacilli and oropharyngeal anaerobic microorganisms; polymicrobial infection is common. In a few cases, chronic maxillary sinusitis is secondary to dental infection. Fungal infections (Aspergillus, Sporothrix, Pseudallescheria) may be chronic and tend to strike older and immunocompromised patients.

Allergic fungal sinusitis is a form of chronic sinusitis characterized by diffuse nasal congestion, markedly viscid nasal secretions, and, often, nasal polyps. It is an allergic response to the presence of topical fungi, often Aspergillus, and is not caused by an invasive infection.

Invasive fungal sinusitis Invasive Sinusitis in Immunocompromised Patients Sinusitis is inflammation of the paranasal sinuses due to viral, bacterial, or fungal infections or allergic reactions. Symptoms include nasal obstruction and congestion, purulent rhinorrhea... read more is an aggressive, sometimes fatal, infection in immunocompromised patients, usually caused by Aspergillus or Mucor species.

In an upper respiratory infection (URI), the swollen nasal mucous membrane obstructs the ostium of a paranasal sinus, and the oxygen in the sinus is absorbed into the blood vessels of the mucous membrane. The resulting relative negative pressure in the sinus (vacuum sinusitis) is painful. If the vacuum is maintained, a transudate from the mucous membrane develops and fills the sinus; the transudate serves as a medium for bacteria that enter the sinus through the ostium or through a spreading cellulitis or thrombophlebitis in the lamina propria of the mucous membrane. An outpouring of serum and leukocytes to combat the infection results, and painful positive pressure develops in the obstructed sinus. The mucous membrane becomes hyperemic and edematous.

Acute and chronic sinusitis cause similar symptoms and signs, including purulent rhinorrhea, pressure and pain in the face, nasal congestion and obstruction, hyposmia, halitosis, and productive cough (especially at night). Often the pain is more severe in acute sinusitis. The area over the affected sinus may be tender, swollen, and erythematous.

Malaise may be present. Fever and chills suggest an extension of the infection beyond the sinuses.

The nasal mucous membrane is red and turgescent; yellow or green purulent rhinorrhea may be present. Seropurulent or mucopurulent exudate may be seen in the middle meatus with maxillary, anterior ethmoid, or frontal sinusitis and in the area medial to the middle turbinate with posterior ethmoid or sphenoid sinusitis.

Manifestations of complications include periorbital swelling and redness, proptosis, ophthalmoplegia, confusion or decreased level of consciousness, and severe headache.

Sinus infections are usually diagnosed clinically. Imaging is not indicated in acute sinusitis unless there are findings that suggest complications, in which case CT is done. In chronic sinusitis, CT is done more often, and x-rays of the apices of the teeth may be required in chronic maxillary sinusitis to exclude a periapical abscess.

Chronic sinusitis is a common incidental finding in patients who have a head CT for other reasons (eg, patients with headache with or without mild head injury) but is rarely the cause of the patient's symptoms.

Microbial cultures are rarely done because a valid culture requires a sample obtained by sinus endoscopy or sinus puncture; culturing a swab of nasal secretions is inadequate. Cultures are typically done only when empiric treatment fails and in immunocompromised patients and some hospital-acquired causes of sinusitis.

In acute sinusitis, improved drainage and control of infection are the aims of therapy. Steam inhalation; hot, wet towels over the affected sinuses; and hot beverages help alleviate nasal vasoconstriction and promote drainage.

Topical vasoconstrictors, such as phenylephrine 0.25% spray every 3 hours or oxymetazoline every 8 to 12 hours, are effective but should be used for a maximum of 5 days or for a repeating cycle of 3 days on and 3 days off until the sinusitis is resolved. Systemic vasoconstrictors, such as pseudoephedrine 30 mg orally (for adults) every 4 to 6 hours, are less effective and should be avoided in young children.

Saline nasal irrigation may help symptoms slightly but is cumbersome and uncomfortable, and patients require teaching to execute it properly; it may thus be better for patients with recurrent sinusitis, who are more likely to master (and tolerate) the technique.

Corticosteroid nasal sprays can help relieve symptoms but typically take at least 10 days to be effective.