Antibiotic-Refractory Sinusitis

A 64-YEAR-OLD MAN WITH A HISTORY OF CHRONIC SINUSITIS PRESENTS WITH left periorbital swelling and subtle left ptosis (FIGURE 1). His past medical history is otherwise unremarkable. He was treated with amoxicillinclavulanate, 875 mg/125 mg, twice per day for 10 days for presumed sinusitis. He experienced mild temporary improvement. Symptoms recurred within a month, and he was given a second course of amoxicillin. Physical examination reveals worsening left periorbital swelling, unilateral nasal blockade, and persistent subtle left ptosis. The neurological examination results are normal, and ptosis is thought to be secondary to palpebral swelling. Lymphadenopathy and hepatosplenomegaly are absent. Laboratory test results are unremarkable. What Would You Do Next?