Persistent asthma has an accumulative impact on the loss of smell in patients with nasal polyposis

Background: Loss of sense of smell is one of the most frequent complaints in patients with nasal polyposis (NP). The aim of this study was to evaluate the impact of asthma and its severity on the sense of smelt Material and methods: Patients with massive NP and healthy controls were included. More than half of patients presented with asthma. Olfactometry by Barcelona Smell Test 24, nasal symptoms score, nasal endoscopy, allergy study, and paranasal sinus CT scan were assessed. Results: NP patients showed a significant impairment in smell detection, identification, and forced choice compared to the control. Asthmatics reported lower scores for detection, identification, and forced choice than non-asthmatic patients. Patients with persistent asthma had an increased impairment of sense of smell on detection, identification, and forced choice than patients with intermittent asthma. No significant differences were found between mild, moderate, and severe persistent asthmatics. Paranasal sinuses opacification was inversely correlated with smell detection, identification and forced choice. Conclusion: These findings suggest that patients with NP have an impaired sense of smell, that asthma -particularly persistent asthma- has a further impact on sense of smell, and that loss of smell may be used as a clinical tool to identify the severity of both NP and asthma.