Recovery of smell sense loss by mepolizumab in a patient allergic to dermatophagoides and affected by chronic rhinosinusitis with nasal polyps

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) frequently presents with dysfunction or loss of thesense of smell, resulting in a signifcant impairment in quality of life. The medical treatments currently available mayimprove the olfactory function in patients with CRSwNP, but such an outcome is generally only transitory. We reportthe case of a patient with CRSwNP who completely recovered from smell sense loss by treatment with mepolizumab.Case presentation: The patient was a 62-year-old female who has severe asthma induced by allergy to Dermatophagoides and concomitant CRSwNP. Any treatment for the latter, including oral and injective corticosteroids, was unsuccessful in the loss of smell. Due to the satisfaction of admission criteria to mepolizumab treatment for severe asthma,treatment was initiated on March 2018, resulting in good clinical control of both asthma and CRSwNP, and particularlyin complete recovery of the smell loss after 4 months of treatment and still persisting.Conclusion: In this case report, the treatment with mepolizumab in a patient allergic to Dermatophagoides andafected by CRSwNP was associated with an improvement of anosmia. That fnding may be explained by a reductionof the nasal obstruction by nasal polyps