Effectiveness of Platelet‐Rich Plasma for COVID‐19‐Related Olfactory Dysfunction: A Controlled Study

Abstract

ObjectiveTo investigate the effectiveness of platelet‐rich plasma (PRP) injection into the olfactory clefts of coronavirus disease 2019 (COVID‐19) patients with persistent olfactory dysfunction (OD).Study DesignControlled study.SettingMulticenter study.MethodsFrom March 2022 to November 2022, COVID‐19 patients with persistent OD were recruited from three European hospitals to undergo PRP injections into the olfactory clefts. Olfactory function was evaluated at baseline and 10 weeks postinjection with the Olfactory Disorder Questionnaire (ODQ) and threshold, discrimination, and identification (TDI) test. Data were compared with a control group of untreated patients.ResultsEighty‐one patients who underwent PRP injection and 78 controls were included. Sixty‐five PRP patients (80.3%) experienced subjective smell improvement after a mean duration of 3.4 ± 1.9 weeks. The parosmia, life quality statement, and ODQ sub‐ and total scores significantly decreased from pre‐ to 10‐week postinjection in the PRP group. The TDI sub‐ and total scores significantly increased 10 weeks postinjection. In controls, the ODQ score did not change over time, while the discrimination, identification, and total TDI scores significantly increase after 10 weeks of follow‐up. The 10‐week TDI and ODQ scores were significantly better in the PRP group compared with the controls.ConclusionPatients who underwent PRP injection reported better 10‐week subjective and objective smell outcomes than controls. Future randomized‐controlled studies using saline injection into the olfactory cleft of controls are needed to determine the superiority of PRP over placebo.

Platelet-Rich Plasma (PRP) in the Treatment of Long COVID Olfactory Disorders: A Comprehensive Review

“…Even though it was subjective, patients' pain ratings ranged from mild to moderate. However, Lechien J.R. et al did not emphasize side effects in their follow-up study, suggesting that such events may not have been a substantial concern or were managed effectively in the controlled setting [60].…”

“…The unique characteristics and demographics of each patient-including age, sex, overall health status, and the presence of underlying medical conditions-can significantly affect how one might respond to PRP therapy [56]. For instance, younger patients with robust healing capabilities may experience quicker and more complete recovery than older individuals or those with comorbidities that may impede the regenerative process [57][58][59][60].…”

Platelet-Rich Plasma for Patients with Olfactory Dysfunction: Myth or Reality? A Systematic Review

“…Similarly, Lechien J.R. et al performed two studies [37,38]. In the first one [37], they enrolled 87 patients with anosmia, hyposmia, or parosmia, with a mean duration of 15.7 months.…”

“…The improvement in smell was seen after an average of 3.6 ± 1.9 weeks. Subsequently, the same group [38] further investigated the effects of PRP injection on 81 patients affected by C19OD, offering a comparison with a control group of 78 untreated patients in a multicenter controlled study. The OD duration was 15.7 and 11.0 months in the PRP and control groups, respectively.…”