Obstruction to mucociliary flow, such as mucosal edemaresulting from the common cold, impedes sinus drainage andpredisposes to bacterial proliferation. In 90% of children withacute sinusitis, the bacterial causes are Streptococcus pneumoniae, nontypable Haemophilus influenzae, Moraxella catarrhalis,Staphylococcus aureus, and group A streptococcus. Anaerobesemerge as important pathogens in subacute and chronic sinusitis. Indwelling nasogastric and nasotracheal tubes predisposeto nosocomial sinusitis, which may be caused by gram-negativebacteria (Klebsiella or Pseudomonas). Antibiotic therapy predisposes to infection with antibiotic-resistant organisms. Sinusitis in neutropenic and immunocompromised persons may becaused by Aspergillus or the Zygomycetes (e.g., Mucor, Rhizopus).
The true incidence of sinusitis is unknown. The common cold is the major predisposing factor for developing sinusitis at allages. Other risk factors include allergy, cystic fibrosis, immunodeficiency, human immunodeficiency virus (HIV) infection,nasogastric or nasotracheal intubation, immotile cilia syndrome,nasal polyps, and nasal foreign body. Sinusitis also is a frequent problem in immunocompromised children after organtransplantation.
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Clinical manifestations most commonly include persistent, mucopurulent, unilateral or bilateral rhinorrhea, nasal stuffiness, and cough, especially at night. Less common symptoms include a nasal quality to the voice, halitosis, facial swelling, facial tenderness and pain, and headache. Sinusitis may exacerbate asthma.
Culture of the nasal mucosa is not useful. Sinus aspirate culture is the most accurate diagnostic method but is not practical or necessary in immunocompetent patients.
Plain x-ray and computed tomography may reveal sinus clouding, mucosal thickening, or an air-fluid level. Abnormal radiographic findings do not differentiate infection from allergic disease; computed tomography and magnetic resonance imaging often show abnormalities, including air-fluid levels, in the sinuses of asymptomatic persons. Conversely normal radiographs have high negative predictive value for bacterial sinusitis.
The diagnosis usually is based on history and physical findings for longer than 10 to 14 days without improvement or increased severity of symptoms compared to the common cold.
Amoxicillin-clavulanate for 10 to 14 days is recommended as first-line therapy of sinusitis in children. High-dose therapy is recommended for children at increased risk for resistant bacteria (antibiotic treatment in the preceding 1 to 3 months, day care attendance, age <2 years, high rates of antimicrobial resistance locally). Levofloxacin is recommended for children with type I hypersensitivity to penicillins. Clindamycin plus a third generation cephalosporin (cefixime, cefpodoxime) is recommended for children with non-type I hypersensitivity.
Complications include orbital cellulitis, epidural or subdural empyema, brain abscess, dural sinus thrombosis, osteomyelitis of the outer or inner table of the frontal sinus (Pott puffy tumor), and meningitis. These all should be managed with sinus drainage and broad-spectrum parenteral antibiotics. Sinusitis also may exacerbate bronchoconstriction in asthmatic patients.