Low-Dose Erythromycin Therapy for Olfactory Disorder in Patients with Chronic Paranasal Sinusitis.

Low-dose erythromycin (EM) therapy has been reported to be effective for chronic paranasal sinusitis, but olfactory disorder was not cured although nasal discharge and nasal obstruction showed a good response. In the present study, we examined the efficacy of lowdose EM therapy systematically in 24 patients with olfactory disorder caused by chronic paranasal sinusitis who were treated with 400 or 600 mg of EM per day for 3 to 8 months. Eighteen patients showed clouded sinuses and/or obstruction of the olfactory cleft in the nose and paranasal sinus X-rays (Group S), and six patients showed no pathological findings in the radiological examination (Group C). We measured the clouded area in the paranasal sinuses and the olfactory cleft before and after EM therapy. Subjective improvement of the olfactory disorder was noted in 79% and objective improvement of olfaction test (T&T olfactogram) results was noted in 61% of Group S whereas the respective percentage in Group C were 0% and 16%. The patients with improved olfaction showed widening of the olfactory cleft but no change of the clouded area in the paranasal sinuses. We conclude that the improvement of olfaction in patients with chronic paranasal sinusitis is due to effect of EM on the olfactory pathology.