The use of platelet‐rich plasma in treatment of olfactory dysfunction: A pilot study

Abstract

Background: Olfactory dysfunction is a prevalent problem with a significant impact on quality of life and increased mortality. Limited effective therapies exist. Plateletrich plasma (PRP) is an autologous biologic product with anti-inflammatory and neuroprotective effects. This novel pilot study evaluated the role of PRP on olfactory neuroregeneration in patients with hyposmia.Methods: Seven patients who had olfactory loss greater than 6 months in duration, no evidence of sinonasal inflammatory disease, and no improvement with olfactory training and budesonide topical rinses were enrolled in this preliminary study.Patients received a single intranasal injection of PRP into the mucosa of the olfactory cleft. The Sniffin' Sticks olfactory test consisting of threshold, discrimination, and identification measurements (TDI) was administered at the beginning of the study and at 1 and 3 months.Results: All patients reported a subjective improvement of their smell shortly after injection but then stabilized. At 3-month post-treatment, two patients with functional anosmia (TDI < 16) did not improve significantly. Five patients with hyposmia (TDI > 16 but <30) showed an improvement with 60% achieving normosmia (TDI > 30) at 3-month follow-up. On average, patients with baseline TDI > 16 improved by 5.85 points with the most significant improvement in the threshold subcomponent. There were no adverse outcomes from intranasal PRP injections.Conclusion: PRP appears safe for use in the treatment of olfactory loss, and preliminary data suggest possible efficacy, especially for those with moderate yet persistent loss. Further studies will help determine optimal frequency and duration of use.

Olfactory epithelium histopathological findings in long-term coronavirus disease 2019 related anosmia

“…There is evidence to support steroid rinses, but not intranasal steroid sprays; 33 this may reflect the greater ability of steroid rinses to reach the olfactory epithelium. In a small pilot study, 34 submucosal injection of platelet rich plasma into the olfactory epithelium in seven patients with hyposmia was associated with significant improvement, but no benefit was found in two anosmic patients. There was no control arm in that study, but further study is certainly warranted.…”

COVID-19 related olfactory dysfunction

“…Platelet-rich plasma (PRP) is known to have anti-inflammatory and pro-regenerative properties, which include upregulation of growth factors including transforming growth factor, vascular endothelial growth factor, epidermal growth factor, and insulin-like growth factor, and may neurodegeneration. A small pilot study [ 62 ▪ ] examined the effectiveness of PRP injection into the olfactory cleft in seven patients. Results were recorded on the 1st and the 3rd month using Sniffin’ Sticks; two patients with anosmia have no improvement, five patients with hyposmia showed improvement.…”

Riech- und Schmeckstörungen

“…In einer Pilotstudie wurde bei Patienten mit persistierender Riechstörung PRP einmalig unter endoskopischer Visualisierung in die Riechspalte gespritzt. Nach der Intervention verzeichneten die Patienten zunächst eine subjektive Verbesserung ihrer Riechstörung, danach stagnierte die Verbesserung jedoch [ 74 ].…”