I am happy to respond to the letter by Dr Gross regarding my study on the microbiology of acute and chronic frontal sinusitis,1 and for the opportunity to clarify the questions posed by him. All specimens included in the study were collected during sinus surgery directly from the frontal sinus. Dr Gross is correct to point out that specimens obtained using endoscopy have a higher rate of possible contamination. However, among the 13 patients with chronic frontal sinusitis, an endoscopic approach was used on only 4 occasions.
Brook I. "Bacteriology of Acute and Chronic Frontal Sinusitis": A Reply—Reply. Arch Otolaryngol Head Neck Surg. 2003;129(4):497. doi:10.1001/archotol.129.4.496-a