The study will be conducted to evaluate :

The efficacy of Platelet Rich plasma in treatment of smell disorders post severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via the growth factors involved in accelerating and enhancing healing.

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.

PRP contains many growth factor which have a neuroregenerative feature as well as therapeutic effect

Inclusion Criteria:

1. patient age above 18 who suffer from anosmia post severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 more than two weeks
2. Normal airway passage
3. CT Nose and Para nasal sinuses does not show any nasal lesion

Exclusion Criteria:

1. Lesions obstruct airway as nasal polyps, tumors, chronic sinusitis and severe nasal septum deviation
2. Previous Sino nasal surgery
3. Atrophic rhinitis
4. Diabetic patients and those with medical history of bleeding disorders
5. Recieving any medication affect platelets or bone marrow function for 2 weeks prior to testing