The ethmoid and the maxillary sinuses form in the third to fourth gestational month and, accordingly, are present at birth. The sphenoid sinuses are generally pneumatized by 5 years of age; the frontal sinuses appear at age 7 to 8 years but are not completely developed until late adolescence. The paranasal sinuses are a common site of infection in children and adolescents.1 These infections are important as a cause of frequent morbidity and rarely may result in life-threatening complications. It may be difficult to distinguish children with uncomplicated viral upper respiratory infections or adenoiditis from those with an episode of acute bacterial sinusitis.2 Most viral infections of the upper respiratory tract involve the nose and the paranasal sinuses (viral rhinosinusitis).3 However, bacterial infections of the paranasal sinuses do not usually involve the nose. When the patient with bacterial infection of the paranasal sinuses has purulent (thick, colored, and opaque) nasal drainage, the site of infection is the paranasal sinuses; the nose is simply acting as a conduit for secretions produced in the sinuses.