Diagnosis

The most commonly used basis of diagnosing chronic pediatric rhinosinusitis is clinical judgment. Transillumination of the sinuses in children is difficult to perform and unreliable, especially in patients younger than 10 years of age because of increased thickness of both the soft tissue and the bony vault.3'23 The value of ultrasonography is controversial, and has a very limited or no role in evaluating rhinosinusitis in children20'24-26 Similarly, plain radiographs have limited value in this setting;27 interpretation in infants and young children is often difficult, there is poor correlation with ethmoid disease, and the significance of sinus clouding is uncertain.28 Furthermore, plain sinus films do not provide visualization of the osteomeatal complex, a cornerstone in the diagnosis of rhinosinusitis.12 In a study comparing plain sinus films with coronal CT scans taken within hours of each other in children displaying symptoms compatible with chronic rhinosinusitis, there was a lack of correlation between the two methods in 74% of the patients.22 The investigators concluded that plain films both over- and underestimate sinus findings.22 Radiographic examination of the nasopharynx, however, may be adjunctively helpful in determining the size of the adenoids, yet this does not replace nasopharyngoscopy; adenoidal tissue size alone does not necessarily correlate with chronic inflammation.15

Imaging is not necessary to diagnose uncomplicated pediatric chronic rhinosinusitis. When indicated, however, fine-cut coronal CT is the imaging modality of choice because of its ability to resolve both bone and soft tissue.29 The need for caution when considering CT evaluation must be emphasized, as the incidence of bony or mucosal disease of the paranasal sinuses in asymptomatic children may be as high as 50% on imaging.30,31 In children with symptoms and signs compatible with chronic rhinosinusitis, CT scanning is most frequently performed if surgery is being considered, or if the patient has a complicated course or a systemic disorder. According to the Brussels consensus meeting, the complete list of indications for CT scanning in the assessment of pediatric rhinosinusitis includes:17

1. Evaluation of the surgical candidate

2. Presence of suppurative intraorbital or intracranial complications (excluding orbital cellulitis)

3. Symptomatic immunocompromised host

4. Severe illness or toxic condition

5. Acute illness that does not improve with medical therapy in 48 to 72 h

In comparison to CT, magnetic resonance imaging (MRI) provides optimal visualization of soft tissues but has no bone resolution. This imaging modality thus has no use in routine evaluation of the paranasal sinuses, and cannot be used reliably as a preoperative guide. MRI is most often reserved for children with suspected neoplasm, congenital mass, intraorbital/intracra-nial complications, or intravenous contrast allergy.32,33

Microbiologic assessment is not necessary in cases of routine evaluation of uncomplicated chronic rhinosinusitis in children, although it does have a role in recalcitrant and complicated disease. Results of most surface cultures have no predictive value, and thus nose, throat, and nasopharyngeal cultures cannot be recommended as guides to the bacteriology on therapy for chronic rhinosinusitis.25 Cultures of pus taken directly from the middle meatus do, however, correlate well with maxillary antral and ethmoid cultures,34,35 although there is no consensus regarding whether middle meatal cultures can substitute for sinus aspirations.17 Indications for maxillary sinus aspiration or puncture in children parallel indications for CT scanning and include symptomatic sinus disease in an immuno-compromised host, suppurative complications, severe illness or a toxic condition, and acute illness unresponsive to therapy within 48 to 72 h.17 This technique is best performed transnasally to avoid injury to dentition and the natural ostium. After sterilization of the puncture site, a needle on a syringe is directed beneath the inferior turbinate and advanced through the lateral nasal wall.2 Aspirated secretions are submitted for gram stain and aerobic and anaerobic cultures. Bacterial counts of greater than 104 colony-forming units (CFU)/ml reflect a high degree of confirmation of infection, rather than contamination.3

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