The initial symptoms described in the first cases of COVID-19 were mainly fever and respiratory signs. Recently, there has been an increase in cases of hyposmia without associated nasal obstruction or rhinorrhea. Although we do not yet know the long-term consequences of COVID-19 on olfaction, there is evidence in the literature demonstrating that post-viral hyposmias are an important source of long-term olfactory disorders, impacting quality of life.

Usually, the treatment of viral hyposmias is based on local and/or general corticosteroid treatment combined with saline nasal irrigation at the onset of signs. Because of the possible development of severe forms of the SARS-Cov-2 infection, the French Society of Otorhinolaryngology has advised against treatment by corticosteroid therapy and nasal irrigation. However, as the virus is present in the nasal fossae on average for 20 days, persistent hyposmia at 30 days would probably result from an inflammatory or neurological damage to the nasal slits or olfactory bulb. Local treatment with corticosteroids could then be instituted from 30 days after the onset of symptoms of COVID-19 without risk of dissemination.

In persistent hyposmia other than chronic rhinosinusitis, the only treatment that has proven its efficacy is nasal irrigation associated with budesonide and olfactory rehabilitation. However, this drug does not have marketing authorisation in France for this indication.

This is a multicenter randomized trial to evaluate the efficacy of local budesonide (nasal irrigation) in the management of persistent hyposmia in COVID-19 patients.

Inclusion Criteria:

• Patient over 18 years of age;
• Patient with a suspected SARS-CoV-2 infection in a epidemic context, whether or not confirmed by PCR, or contact close to a PCR-confirmed case, typical chest CT scan (unsystematized frosted glass areas predominantly sub-pleural, and at a later stage of alveolar condensation with no excavations neither nodules nor masses) or positive serology ;
• Patient with isolated acute hyposmia persisting at D30. of the onset of signs of CA-MRSA-CoV-2 infection;
• Absence of PCR-confirmed SARS-CoV-2 portage at the time of inclusion

Exclusion Criteria:

• Known hypersensitivity to budesonide or to any of the excipients of the medicine;
• Hemostasis disorder, or epistaxis;
• Oromo-oral-nasal and ophthalmic herpes virus infection;
• Long-term corticosteroid treatment;
• Treatment with potent CYP3A4 inhibitors (e.g., CYP3A4 inhibitors); ketoconazole, itraconazole, voriconazole, posaconazole, clarithromycin, telithromycin, nefazodone and HIV proteases) ;
• Forms of CoV-2-SARS with respiratory signs or other than anosmia persisting at 30 days from the onset of symptoms;
• Hyposmia persisting for more than 90 days after onset of symptoms;
• Other causes of hyposmia revealed on interrogation or an MRI;

Patients with persistent hyposmia related to a SARS-CoV-2 infection