['Endoscopic microdebrider-assisted inferior turbinoplasty is a newly developed surgical technique to treat patients with nasal obstruction. Although the procedure has been reported to be safe and effective, we tested the hypothesis that the prognosis might deteriorate with time in allergic rhinitis patients as identified by a positive allergen test in patients who have a persistent regional inflammation of the nose. We assessed the degree of nasal obstruction in a prospective cohort to investigate whether positive allergen test predicts outcome.', 'In 70 consecutive patients, the symptom of nasal obstruction was evaluated subjectively by a visual analog scale (VAS) and objectively by acoustic rhinometry using cross-sectional area of the second notch (CSA-2) and nasal cavity volume before operation, and 3 months, 12 months after operation, respectively. Then, patients were classified and compared according to the multiple-antigen simultaneous test (MAST).', 'Both MAST(+) and MAST(-) groups showed statistically significant improvement in VAS score, CSA-2, and nasal cavity volume at 12 months after operation (p < 0.01). Of note, MAST(+) patients showed less favorable results than MAST(-) patients at 12 months after operation (p < 0.05).'] Do patients with positive allergen test have less favorable outcome after endoscopic microdebrider-assisted inferior turbinoplasty?