Rhinosinusitis (infection or inflammation of the mucous membranes lining the paranasal sinuses) is one of the most common health problems in our country.1-4 Each year, it affects about 37 million Americans, costs nearly $6 billion, and accounts for nearly 1 million lost days from work.5
Rhinosinusitis can be acute, chronic, or recurrent. The acute form lasts for 3 weeks or less.6 When 4 or more distinct episodes of acute rhinosinusitis occur within a year, the patient is considered to have recurrent rhinosinusitis. Rhinosinusitis is considered to be chronic when, following the patient's treatment for acute rhinosinusitis, either bothersome symptoms persist for 12 weeks or CT changes persist for 4 weeks. The chronic form of rhinosinusitis is the most common, affecting about 32 million Americans per year.6 It typically lasts for weeks, but it can persist for months or years.6
In this article, I will focus on diagnosis and management of chronic rhinosinusitis. An accompanying Patient Education Guide (page 452) will provide your patients with some answers to common questions about chronic rhinosinusitis.CAUSES
Most cases of rhinosinusitis start as a viral or bacterial upper respiratory tract infection (URTI). About 10% of cases of maxillary rhinosinusitis have a dental origin.7 The most common bacterial causes are Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes, and Streptococcus viridans.8 Anaerobic bacte-ria account for only about 7% of acute infections. The most common anaerobic bacteria that cause chronic rhinosinusitis are the anaerobic streptococci, Bacteroides species, and Fusobacterium.
Infection typically begins in the mucosal layer of the sinus, then spreads into the glandular cells and into the deeper layers of the sinus cavities.9 Stasis of trapped respiratory secretions can lead to bacterial overgrowth and chronic disease (see "Sinus function: A review of the basics").10-12
Rhinosinusitis can also be related to fungal infection. Invasive fungal rhinosinusitis is most common in persons who are diabetic or immunocompromised. A distinct entity--allergic fungal sinusitis (AFS)--occurs in immunocompetent patients who have localized immunologic hypersensitivity reactions to fungal colonization of the sinuses.3 AFS is usually caused by Bipolaris spicifera or Aspergillus, Curvularia, Helminthosporium, Alternaria, or Fusarium species.3
Chronic rhinosinusitis can have a noninfectious origin. Physical obstruction, such as that caused by a deviated septum or nasal polyps, can cause entrapment and pooling of respiratory secretions. Diseases or conditions that cause thickening of respiratory mucus, such as cystic fibrosis, can delay transit of mucus through the sinuses. Asthma and allergies to airborne irritants, such as dust, mold, pollen, and pollutants, increase inflammation in the nasal passages and sinuses.PATIENT EVALUATION
The signs and symptoms of rhinosinusitis often resemble those of allergy or a viral URTI, except for their duration (Table 1). The chief symptom of URTI is nasal congestion without persistent or worsening head congestion, headache, facial pain, or fatigue. Symptoms of URTI, unlike those of rhinosinusitis, peak at days 3 to 5 and resolve within 7 to 10 days. Differentiating rhinosinusitis from a viral URTI helps avoid unnecessary treatment with antibiotics.
The location of sinus pain can vary, depending on the sinuses affected. Pain in the forehead suggests frontal sinus involvement, while aching in the upper jaw and teeth can be caused by infection in the maxillary sinuses. Patients with inflammation in the ethmoidal sinuses may have periorbital swelling, nasal tenderness, a stuffy nose, and loss of ability to smell.
Earaches, neck pain, and pain at the top of the head are consistent with sphenoidal infection. However, the areas of pain are not always clearly defined, especially if multiple sinus cavities are inflamed. Signs of inflammation include purulent drainage, polyps, polypoid changes, and mucosal abnormalities in the middle meatus. The diagnosis of chronic rhinosinusitis can be based on the patient's history and symptoms. The presence of purulent secretions is one of the strongest signs of rhinosinusitis. On examination, purulent drainage may be evident as anterior rhinorrhea or posterior pharyngeal drainage with associated symptoms of sore throat and cough. Nasal discharge is thick and yellow to yellowish green when it is associated with bacterial infection; it is thin and clear when associated with allergies or viral infection.
Examine the patient's nose for a deviated nasal septum, nasal polyps, and epistaxis. Foreign bodies and tumors may mimic symptoms of rhinosinusitis, but they usually cause unilateral symptoms. Check the ears for signs of associated otitis media, and auscultate the chest for wheezing, which may suggest asthma.
Cultures are notoriously unreliable for determining the cause of rhinosinusitis, because of nasal contamination. The exception is when specimens for culture are obtained via sterile antral puncture, which is both difficult and impractical to perform in a clinical setting.13,14 A nasal smear, however, can be useful: the presence or absence of polymorphonuclear cells suggests bacterial or viral infection, respectively. When rhinosinusitis is related to allergy, the smear typically contains eosinophils.
Examination of the sinus contents by endoscopy or rhinoscopy yields clues to fungal involvement. In patients with AFS, the sinus contains allergic mucin, a thick gray-brown secretion containing Charcot-Leyden crystals and fungal elements.3 Patients with fungal rhinosinusitis typically have no evidence of diabetes, immunosuppression, or invasive fungal disease, but their sinus contents contain allergic mucin and fungal elements.
Although some physicians recommend performing imaging studies if the results of the initial workup do not clearly support the diagnosis of chronic rhinosinusitis, I do not find them to be very helpful or cost-effective when done so early in the workup.15