Acute sinusitis is a disease that results from infection of one or more of the paranasal sinuses. A viral infection associated with the common cold is the most frequent etiology of acute sinusitis, most properly termed viral rhinosinusitis. Only a small percentage (2%) of viral rhinosinusitis is complicated by acute bacterial sinusitis. Uncomplicated viral rhinosinusitis usually resolves in 7 to 10 days. Acute bacterial sinusitis is also usually a self-limited disease, with 75% of cases resolving without treatment in one month. However, untreated patients with acute bacterial sinusitis have bothersome morbidity and are at risk of developing intracranial and orbital complications and of possibly developing chronic sinus disease.
Disease is subacute when symptomatic for 4-12 weeks, chronic when > 12 weeks.
Pathophysiology:
The sinuses are normally sterile under physiologic conditions, they open into the nose via small openings called ostia. Purulent sinusitis can occur when ciliary clearance of sinus secretions decreases or when the sinus ostium becomes obstructed, which leads to retention of secretions, negative sinus pressure, and reduction of oxygen partial pressure. This environment is then suitable for growth of pathogenic organisms. Factors that predispose the sinuses to obstruction and decreased ciliary function are allergic, non allergic, or viral insults, which produce inflammation of the nasal and sinus mucosa and result in ciliary dysmotility and sinus obstruction, secretions that are not cleared become hospitable to bacterial growth. Approximately 90% of patients who have viral upper respiratory tract infections (URTIs) have sinus involvement.
Complications of acute bacterial sinusitis are rare but may include meningitis, brain abscess, and periorbital cellulitis.
Paranasal sinuses:
Frontal sinuses: over the eyes in the brow area.
Maxillary sinuses: inside each cheekbone.
Ethmoid sinuses: just behind the bridge of the nose and between the eyes.
Sphenoid sinuses: behind the ethmoids in the upper region of the nose and behind the eyes.
Etiology:
Viral:
Vast majority of cases (Rhinovirus, Influenza virus, Coronavirus, Respiratory syncytial virus, and Adenovirus)
Bacterial:
1- Community-acquired (complicate 2% of viral cases) the most common organisms are Streptococcus pneumonia, Haemophilus influenza and Moraxella catarrhalis.
2- Nosocomial sinusitis can be due to Staphylococcus aureus, Streptococcal spp, Pseudomonas spp, and other gram-negative bacteria (E.coli and Klebsiella), Anaerobic bacteria and yeast, especially Candida albicans, have also been recovered from sinus aspirates of some patients with nosocomial sinusitis.
Fungal infection:
Is seen in immunocompromised hosts (uncontrolled diabetes, neutropenia, steroid use).
Risk factors:
Viral upper respiratory infection, allergic rhinitis, asthma, smoking, trauma, dental infections, anatomical variations (tonsillar and adenoid hypertrophy, nasal polyps, deviated septum and cleft palate), immunodeficiency (HIV), cystic fibrosis.
Signs and symptoms:
The clinical presentation of the patient is of limited utility in distinguishing cases of pure viral rhinosinusitis from those with secondary bacterial infection.
Symptoms of acute sinusitis include nasal congestion, purulent nasal discharge, maxillary tooth discomfort, hyposmia, and facial pain or pressure that is worse when bending forward. In addition, headache, fever (nonacute), halitosis, fatigue, cough, ear pain, and ear fullness are all considered clinical manifestations of rhinosinusitis.
Symptoms predictive of bacterial sinusitis:
Persistent symptoms for > 10 days, worsening of symptoms after 5-7 days after initial improvement, persistent purulent nasal discharge.
Symptoms requiring urgent attention:
Visual disturbances (especially diplopia), periorbital swelling or erythema, altered mental status.
Diagnosis:
The clinical diagnosis of acute bacterial sinusitis should be reserved for patients with symptoms lasting seven days or more and who have maxillary pain with tenderness in the face or upper teeth accompanied by purulent nasal secretions. Clinicians should be aware that most cases of acute sinusitis are viral and resolve without antibiotics.
Transillumination of the sinuses: may confirm fluid in sinuses, it is limited because it does not distinguish between viral and bacterial etiology.
Cultures of nasal secretions are not generally useful, limited by lack of sensitivity for detecting sinusitis (nasalpassages are frequently colonized).
Radiography has traditionally been used to aid in the diagnosis of acute bacterialsinusitis, but it is not very specific for the diagnosis of bacterial compared to nonbacterial sinusitis and therefore has a limited role.
CT scan is the procedure of choice for evaluation of regional anatomy of the nasal cavity and paranasal sinuses and for determining the true extent of disease for that moment in time, it considered by most physicians the gold standard because of its increased sensitivity and specificity over plain radiographs.
Sinus puncture and aspiration of purulent secretions is so sensitive but not used much due to invasiveness and pain. This test is reserved for recurrent or complicated cases.
Treatment:
General measures: adequate hydration, steam inhalation 20-30 min t.i.d, saline nose drops, avoid exposure to cigarette smoke.
Many clinicians believe that acute sinusitis is a self limiting disease in most cases and that antibiotics have little effect on the natural course of the disease. This Acute viral sinusitis are viral is self limiting and antibiotic should not be used.
Antibiotics:
They appear to have a slight advantage over placebo, most patients improve without therapy.
Major issue: distinguish bacterial from viral.
Treat 10-14 days unless otherwise specified.
Choice should be based on antibiotic resistance in the community.
Multible meta-analyses have demonstrated no benefit of newer antibiotics over amoxicillin, trimethoprim-sulfamethoxazole, or doxycyclin.
1st line therapy is Amoxicillin: (adult) 500-1000 mg t.i.d, (children) 80-90 mg/kg/day divided q8h
Trimethoprim-sulfamethoxazole: 160 mg/ 800 mg q12h in adults and 8-12 mg/kg/day of trimethoprim component divided q12h for children.
Doxycyclin 100 mg PO b.i.d.
If we suggest high incidence of antibiotic resistance, we can use the 2nd line therapy:
amoxicillin-clavulanate 1 g bid (adults), 30 mg/kg/day (children)
Cefuroxime: 250 mg bid (adults), 30 mg/kg/day (children)
Cefdinir: 600 mg/d PO (adults), 14 mg/kg/day (children)
Clarithromycin: 500 mg bid (regular) or 1 g qd (extended) (adults), 15 mg/kg/day (children)
Levofloxacin: 500 mg per day in adults.
Azithromycin: 500 mg on day 1 and 250 mg on days 2-5 in adults, 10 mg/kg on day 1 and 5 mg/kg on days 2-5 in children.
Other medications:
- Decongestants:
Oral: Psudoephedrine (30-60 mg every 4 h as needed) or Phenylephrine (for 10-14 days), topical: Oxymetazoline (for 3-5 days to prevent rebound hyperemia)
- Analgesics:
Acetaminophen, Aspirin, NSAIDs, Acetaminophen-codeine.
- Antihistamines:
Antihistamines are beneficial for reducing osteomeatal obstruction in patients with allergies and acute sinusitis; however, they are not recommended for routine use for patients with acute sinusitis, because they may worse the symptoms by causing dryness of the mucus secretions.
- Nasal steroids:
Fluticasone, Mometasone, Budesonide, Beclomethasone.
- Leukotriene inhibitors:
Montelukast (Singulair®) maybe indicated in patients with concomitant asthma.
Fri Jun 08, 2007 10:33 am
