Medical Treatment of Pediatric Sinusitis Workup

Laboratory tests are normally not particularly helpful in making the diagnosis of sinusitis. However, they can be essential in determining whether associated conditions such as allergic rhinitis, cystic fibrosis, or immunodeficiency are present. In addition, in patients with suppurative complications or in a very toxic-appearing child, some blood work and cultures may be helpful for determining treatment.

See the list below:

• CT scanning

  • CT scanning is the criterion standard for evaluation of both mucosal inflammation and anatomic abnormalities in the paranasal sinuses. CT scanning provides a reliable picture of the ostiomeatal complex in a noninvasive fashion.

  • CT scanning demonstrates exceptional diagnostic accuracy for the diagnosis of pediatric sinusitis with excellent sensitivity and specificity. However, its predictive value depends on prevalence of chronic rhinosinusitis in the population being evaluated. ^[10]

  • CT scanning is mandatory before endoscopic sinus surgery and very valuable when an impending complication of sinusitis such as periorbital or intracranial involvement exists.

  • Thin-cut axial and coronal images of the paranasal sinuses are optimal. A limited number of coronal images alone are used by some as a screening method.

  • Contrast is not necessary for routine sinus evaluation, but it is necessary when a complication such as orbital or intracranial abscess is suspected.

  • The best images for chronic sinusitis are taken at the point of maximal wellness, usually during the last week of a 4-week course of maximal medical therapy. Maximal medical therapy includes appropriate antibiotics and possibly nasal saline irrigations, topical nasal steroids, or decongestants.

  • A 45% occurrence of incidental sinusitis/opacification has been found on pediatric facial CT scans taken for other reasons. In an asymptomatic patient, no treatment or further workup is necessary. In children younger than 12 years, mucosal thickening or sinus opacification are associated with only a 50% chance of actual sinusitis. During an acute viral URTI, the sinuses are routinely opacified on CT scan. In the early stages, URTIs do not require treatment with antibiotics.

  • Note anatomic abnormalities, hypoplastic maxillary sinuses, concha bullosa, and changes consistent with cystic fibrosis (eg, medial displacement of the lateral nasal wall) on review of CT scans.

  • A thinning of the surrounding bone with wispy areas of calcium density may be observed in patients with allergic fungal sinusitis.

• Plain radiography/sinus series

  • These studies have a poor correlation with CT scanning; as many as 75% of them either underestimate or overestimate disease.

  • Plain radiography is a fairly inaccurate screening method even for maxillary sinus disease.

  • Inaccuracies are compounded by mucosal tears, asymmetric facial or sinus development, overlying soft tissue, multiple septal walls, sinus overlap, improper exposure, and head rotation.

• MRI: MRI is useful when intracranial complications are suggested or when allergic fungal sinusitis (nonenhancing on T1, bright on T2, central signal void) is suggested.

• Ultrasonography

  • Ultrasonography can be used to evaluate the maxillary sinuses, but results have been somewhat inconsistent.

  • It has not yet gained widespread acceptance in the United States.

See the list below:

• Rigid or flexible nasal endoscopy

  • Nasal endoscopy provides an excellent view of the OMC.

  • It is helpful for evaluation of the adenoid pad.

  • This procedure requires patient cooperation.

• Maxillary sinus puncture

  • This test is the criterion standard for obtaining maxillary sinus cultures.

  • Aerobic and anaerobic culture and sensitivity and Gram staining may enable pathogen-directed antibiotic therapy.

  • Indications for maxillary sinus puncture include the following:

    • Severe toxic illness

    • Acute illness unresponsive to antibiotics within 72 hours

    • Immunocompromised patients

    • Suppurative complications

    • Workup for fever of unknown origin

  • Contents of the maxillary sinus may be aspirated safely through the canine fossa or inferior meatus, but in the pediatric population this often requires a brief general anesthetic. In this instance, the physician may also consider obtaining a culture via the natural maxillary sinus ostia.

• Middle meatal swab

  • Cultures taken from the middle meatus or anterior middle turbinate have good (>80%) correlation with cultures taken from ipsilateral maxillary or ethmoid sinuses.

  • Having a carefully guided endoscopic sample of purulence from the middle meatus is important. Random nasal swabs show little correlation with maxillary cultures.

  • This procedure requires a cooperative child but is definitely less invasive than sinus puncture.

A submucosal inflammatory infiltrate is observed in acute and chronic sinusitis. Only allergic fungal sinusitis has a characteristic finding on histopathologic examination, with Charcot-Leyden crystals and eosinophilia. An abundance of eosinophils may also be seen in the submucosa of any patient with allergic rhinitis.