Value of Platelet-Rich Plasma in Post Severe Acute Respiratory Syndrome Coronavirus 2 Smell Disorders

Smell is essential sensory function for good quality of life as its preservation helps in identifying several harmful odors .

Viral URTIs can lead to olfactory disorders of varying degree and duration 70% of URTI caused by rhinovirus, adenovirus ,influenza and parainfluanza virus Smell disorders are divided into two types Quantitative (anosmia and hyposmia) Qualitative (parosmia and phantosmia) Anosmia is a total loss of smell . hyposmia is a decrease in the sense of smell. parosmia is a distortion of the smell in presence of an existing stimulus . Phantosmia (Cacosmia) is distortion of the smell in absence of an existing stimulus severe acute respiratory syndrome coronavirus2 (SARS-coV-2)which is a global pandemic started in china 2019 one of respiratory tract infection that affect olfaction and cause varying types of smell impairment.

Smell disorders seem to be more common in SARS-coV2 than other respiratory infections as in some patient persist for long time after resolution of respiratory symptoms Current evidence suggest that olfactory impairment results from propensity of SARS-coV2 for neuroinvasion and neurotrophic activities .

Majority of patients experience some level of smell impairment most often temporary as olfactory neuroepithelium has regenerative power .

European study published on 16 July 2020 reported that some patient affected by SARS -coV2 come solely with olfactory symptoms and most of patient recovered within 2 weeks ,smell not recovered in one quarter of patient 15 Once olfactory dysfunction persists more than 2 weeks a therapy should be considered to avoid persistent impairment of smell One of therapies can be used in ttt of smell disorders ( Platelet _rich plasma) PRP is a process in which a small amount of blood from test subject is separated by special centrifugation process.