Effectiveness and Safety of Platelet Rich Plasma (PRP) on Persistent Olfactory Dysfunction Related to COVID-19

Effectiveness and Safety of Platelet Rich Plasma (PRP) on Persistent Olfactory Dysfunction Related to COVID-19: Towards a New Therapeutic Hope

Status

Completed

Phases

Phase 2Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05226546

Enrollment

Registered

2022-02-07

Start date

2021-02-01

Completion date

2021-08-01

Last updated

2022-02-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anosmia, COVID-19

Keywords

PRP, Anosmia, COVID-19

Brief summary

Olfactory dysfunction (OD) is a well know symptom of coronavirus disease 2019 (COVID-19), accounting for 48 to 85% of patients. In 1 to 10% of cases, patients develop a chronic olfactory dysfunction (COD,) lasting more than 6 months. Recently, platelet-rich plasma (PRP) was used in patients with non-COVID-19 COD and authors reported encouraging results. In the present study, the investigators investigated the usefulness and safety of PRP injection in 56 patients with COVID-19 COD. Our results showed that PRP in the olfactory cleft can increase the olfactory threshold one month after the injection. Moreover, our results suggest that timing of treatment may be an important factor and that PRP is a safe treatment because no adverse effects were reported throughout the study

Interventions

DRUGPlatelet rich plasma (PRP)

PRP injections were performed in each olfactory cleft by nasal endoscopy and under local anesthesia, a sniffing stick test was performed before the injection and one month after

OTHERolfactory training

The investigators compare the result of the PRP group to a control group how underwent simple olfactive training for one month. The control group matched for age, gender and olfactory score at baseline. The patients had a sniffing stick test at the beginning and also after one month of olfactory training.

Study design

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Patient chronic olfactory dysfunction lasting more than 6 months after an infection of COVID-19

Exclusion criteria

* Patient under 18 years old * Patient with blood disorder * Blood thinner user * Patient with abnormal findings on nasal endoscopy (e.g., polyposis, rhinosinusitis)

Design outcomes

Primary

Measure	Time frame
efficity of 1 injection of PRP by Sniffing Sick test compare to a simple olfactory training	1 month

Countries

Belgium

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 11, 2026