Randomized Clinical Trial of Intranasal Injection of Platelet-Rich Plasma for Treatment of Parosmia

Inclusion Criteria: * Patients \>= 18 years of age * Patients who have qualitative olfactory distortion * Etiology of qualitative olfactory distortion is due to upper respiratory infection * Quantitative score under the 10th percentile on the SSParoT (HedRang and HedDir) * Quantitative score ≥ 8 on the QOD. * At least 6 months of parosmia but less than 24 months * Patients can have been previously treated with oral and topical steroids but this is not a requirement * Patients will receive concurrent olfactory training - the practice of smelling strong odors (standard of care) * Be able to read and understand English * Be able and willing to provide Informed Consent Exclusion Criteria: * Patients \< 18 years of age, pregnant females, patients who have structural abnormalities on nasal endoscopy or radiographic imaging that would prevent injection into the olfactory cleft * Olfactory loss due to trauma, chronic sinusitis / inflammation / polyps, neoplasms, or neurodegenerative diseases or patients who have had olfactory loss \> 24 months * Patients with bleeding disorders or on blood thinners such as coumadin and plavix