Etiology

The bacterial pathogens causing acute bacterial sinusitis in children and adolescents include Streptococcus pneumoniae (∼30%; Chapter 176), nontypable Haemophilus influenzae (∼20%; Chapter 186), and Moraxella catarrhalis (∼20%; Chapter 188). Approximately 50% of H. influenzae and 100% of M. catarrhalis are β-lactamase positive. About 25% of S. pneumoniae may be penicillin resistant. Staphylococcus aureus, other streptococci, and anaerobes are uncommon causes of acute bacterial sinusitis in children. Although Staphylococcus aureus is an uncommon pathogen for acute sinusitis in children, the increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is a significant concern. H. influenzae, α- and β-hemolytic streptococci, M. catarrhalis, S. pneumoniae, and coagulase-negative staphylococci are commonly recovered from children with chronic sinus disease.

Epidemiology

Acute bacterial sinusitis can occur at any age. Predisposing conditions include viral upper respiratory tract infections (associated with out-of-home daycare or a school-aged sibling), allergic rhinitis, and cigarette smoke exposure. Children with immune deficiencies particularly of antibody production (immunoglobulin G [IgG], IgG subclasses, IgA) (Chapter 118), cystic fibrosis (Chapter 395), ciliary dysfunction (Chapter 396), abnormalities of phagocyte function, gastroesophageal reflux, anatomic defects (cleft palate), nasal polyps, cocaine abuse, and nasal foreign bodies (including nasogastric tubes) can develop chronic sinus disease. Immunosuppression for bone marrow transplantation or malignancy with profound neutropenia and lymphopenia predisposes to severe fungal (aspergillus, mucor) sinusitis, often with intracranial extension. Patients with nasotracheal intubation or nasogastric tubes may have obstruction of the sinus ostia and develop sinusitis with the multiple-drug resistant organisms of the intensive care unit (ICU).

Pathogenesis

Acute bacterial sinusitis typically follows a viral upper respiratory tract infection. Initially, the viral infection produces a viral rhinosinusitis; MRI evaluation of the paranasal sinuses demonstrates major abnormalities (mucosal thickening, edema, inflammation) of the paranasal sinuses in 68% of healthy children in the normal course of the common cold. Nose blowing has been demonstrated to generate sufficient force to propel nasal secretions into the sinus cavities. Bacteria from the nasopharynx that enter the sinuses are normally cleared readily, but during viral rhinosinusitis, inflammation and edema can block sinus drainage and impair mucociliary clearance of bacteria. The growth conditions are favorable, and high titers of bacteria are produced.

Clinical Manifestations

Children and adolescents with sinusitis can present with nonspecific complaints, including nasal congestion, purulent nasal discharge (unilateral or bilateral), fever, and cough. Less-common symptoms include bad breath (halitosis), a decreased sense of smell (hyposmia), and periorbital edema. Complaints of headache and facial pain are rare in children. Additional symptoms include maxillary tooth discomfort and pain or pressure exacerbated by bending forward. Physical examination might reveal erythema and swelling of the nasal mucosa with purulent nasal discharge. Sinus tenderness may be detectable in adolescents and adults. Transillumination reveals an opaque sinus that transmits light poorly.

Diagnosis

The clinical diagnosis of acute bacterial sinusitis is based on history. Persistent symptoms of upper respiratory tract infection, including nasal discharge and cough, for >10-14 days without improvement, or severe respiratory symptoms, including temperature of at least 102°F (39°C) and purulent nasal discharge for 3-4 consecutive days, suggest a complicating acute bacterial sinusitis. Bacteria are recovered from maxillary sinus aspirates in 70% of children with such persistent or severe symptoms studied. Children with chronic sinusitis have a history of persistent respiratory symptoms, including cough, nasal discharge, or nasal congestion, lasting >90 days.

Sinus aspirate culture is the only accurate method of diagnosis but is not practical for routine use for immunocompetent patients. It may be a necessary procedure for immunosuppressed patients with suspected fungal sinusitis. In adults, rigid nasal endoscopy is a less-invasive method for obtaining culture material from the sinus but detects a great excess of positive cultures compared to aspirates. Transillumination of the sinus cavities can demonstrate the presence of fluid but cannot reveal whether it is viral or bacterial in origin. In children, transillumination is difficult to perform and is unreliable. Findings on radiographic studies (sinus plain films, CT scans) including opacification, mucosal thickening, or presence of an air-fluid level are not totally diagnostic (Fig. 372-2). Such findings can confirm the presence of sinus inflammation but cannot be used to differentiate among viral, bacterial, or allergic causes of inflammation.

Figure 372-2 Acute left maxillary sinusitis with an air-fluid level. Note concha bullosa (C).

(From Isaacson G: Sinusitis in childhood, Pediatr Clin North Am 43:1297–1317, 1996.)

Given the nonspecific clinical picture, differential diagnostic considerations include viral upper respiratory tract infection, allergic rhinitis, nonallergic rhinitis, and nasal foreign body. Viral upper respiratory tract infections are characterized by clear and usually nonpurulent nasal discharge, cough, and initial fever; symptoms do not usually persist beyond 10-14 days, although a few children (10%) have persistent symptoms even at 14 days. Allergic rhinitis can be seasonal; evaluation of nasal secretions should reveal significant eosinophilia.

Treatment

It is unclear whether antimicrobial treatment of clinically diagnosed acute bacterial sinusitis offers any substantial benefit. A randomized, placebo-controlled trial comparing 14-day treatment of children with clinically diagnosed sinusitis with amoxicillin, amoxicillin-clavulanate, or placebo found that antimicrobial therapy did not affect resolution of symptoms, duration of symptoms, or days missed from school. Guidelines from the American Academy of Pediatrics recommend antimicrobial treatment for acute bacterial sinusitis to promote resolution of symptoms and prevent suppurative complications, although 50-60% of children with acute bacterial sinusitis recover without antimicrobial therapy.

Initial therapy with amoxicillin (45 mg/kg/day) is adequate for the majority of children with uncomplicated acute bacterial sinusitis. Alternative treatments for the penicillin-allergic patient include trimethoprim-sulfamethoxazole, cefuroxime axetil, cefpodoxime, clarithromycin, or azithromycin. For children with risk factors (antibiotic treatment in the preceding 1-3 mo, daycare attendance, or age <2 yr) for the presence of resistant bacterial species, and for children who fail to respond to initial therapy with amoxicillin within 72 hr, treatment with high-dose amoxicillin-clavulanate (80-90 mg/kg/day of amoxicillin) should be initiated. Azithromycin (or in older children, levofloxacin) is an alternative antibiotic. Failure to respond to this regimen necessitates referral to an otolaryngologist for further evaluation because maxillary sinus aspiration for culture and susceptibility testing may be necessary. The appropriate duration of therapy for sinusitis has yet to be determined; individualization of therapy is a reasonable approach, with treatment recommended for 7 days after resolution of symptoms.

Frontal sinusitis can rapidly progress to serious intracranial complications and necessitates initiation of parenteral ceftriaxone until substantial clinical improvement is achieved (Figs. 372-3 and 372-4). Treatment is then completed with oral antibiotic therapy.

Figure 372-3 Axial plane contrast-enhanced CT scan of an 11 yr old boy with a frontal subperiosteal abscess secondary to acute frontal sinusitis. The CT scan demonstrates a ring-enhancing midline fluid density over the frontal bone.

(From Parikh SR, Brown SM: Image-guided frontal sinus surgery in children, Operative Tech Otolaryngol Head Neck Surg 15:37–41, 2004.)

Figure 372-4 Axial plane contrast-enhanced CT scan of an 11 yr old obtunded girl with a subfrontal lobe abscess secondary to frontal sinusitis. The CT scan demonstrates an eliptiform ring-enhancing fluid-filled cavity adjacent to the frontal lobe with contralateral shift of the midline.

(From Parikh SR, Brown SM: Image-guided frontal sinus surgery in children, Operative Tech Otolaryngol Head Neck Surg 15:37–41, 2004.)

The use of decongestants, antihistamines, mucolytics, and intranasal corticosteroids has not been adequately studied in children and is not recommended for the treatment of acute uncomplicated bacterial sinusitis. Likewise, saline nasal washes or nasal sprays can help to liquefy secretions and act as a mild vasoconstrictor, but the effects have not been systematically evaluated in children.

Complications

Because of the close proximity of the paranasal sinuses to the brain and eyes, serious orbital and/or intracranial complications can result from acute bacterial sinusitis and progress rapidly. Orbital complications, including periorbital cellulitis and orbital cellulitis (Chapter 626) are most often secondary to acute bacterial ethmoiditis. Infection can spread directly through the lamina papyracea, the thin bone that forms the lateral wall of the ethmoidal sinus. Periorbital cellulitis produces erythema and swelling of the tissues surrounding the globe, whereas orbital cellulitis involves the intraorbital structures and produces proptosis, chemosis, decreased visual acuity, double vision and impaired extraocular movements, and eye pain. Evaluation should include CT scan of the orbits and sinuses with ophthalmology and otolaryngology consultations. Treatment with intravenous antibiotics should be initiated. Orbital cellulitis can require surgical drainage of the ethmoidal sinuses.

Intracranial complications can include epidural abscess, meningitis, cavernous sinus thrombosis, subdural empyema, and brain abscess (Chapter 595). Children with altered mental status, nuchal rigidity, or signs of increased intracranial pressure (headache, vomiting) require immediate CT scan of the brain, orbits, and sinuses to evaluate for the presence of intracranial complications of acute bacterial sinusitis. Treatment with broad-spectrum intravenous antibiotics (usually cefotaxime or ceftriaxone combined with vancomycin) should be initiated immediately, pending culture and susceptibility results. In 50% the abscess is a polymicrobial infection. Abscesses can require surgical drainage. Other complications include osteomyelitis of the frontal bone (Pott puffy tumor), which is characterized by edema and swelling of the forehead (see Fig. 372-3), and mucoceles, which are chronic inflammatory lesions commonly located in the frontal sinuses that can expand, causing displacement of the eye with resultant diplopia. Surgical drainage is usually required.

Prevention

Prevention is best accomplished by frequent handwashing and avoiding persons with colds. Because acute bacterial sinusitis can complicate influenza infection, prevention of influenza infection by yearly influenza vaccine will prevent some cases of complicating sinusitis. Immunization or chemoprophylaxis against influenza with oseltamivir or zanamivir may be useful for prevention of colds caused by this pathogen and the associated complications; influenza is responsible for only a small proportion of all colds.