Effectiveness of Platelet-Rich Plasma in Long-Lasting Post-Viral Olfactory Dysfunction: a Case-Series

To investigate the platelet-rich plasma (PRP) effectiveness in patients with a long-lasting postviral olfactory dysfunction (LPOD). Forty-three consecutive patients with a long-lasting postviral OD were prospectively recruited. The injection of 1 mL of PRP was carried out in both olfactory clefts. The pre- to 6-month post-PRP injection change in olfaction was assessed with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) tests. Forty-three patients received bilateral PRP injections (24 females). The mean age of patients was 58.9 ± 16.8 years. The mean duration of LPOD was 8.7 years. The pre to 6-month post-injection mean TDI significantly improved from 10.3 ± 10.2 to 20.12 ± 12.07 (p = 0.001). The mean ODQ significantly decreased from 29.8 ± 13.0 to 23.4 ± 11.3 (p = 0.013). The average change of the TDI and the ODQ were 9.8 and 6.4, respectively. Age was inversely associated with the 6-month threshold score. PRP appears to be a promising therapeutic strategy for long-lasting postviral OD. Our findings support the conduction of controlled randomized trial in this population of patients.