Platelet-rich Plasma in Management of Anosmia (Single Versus Double Injections)

Anosmia is a common problem with a significant impact on quality of life and increased mortality. People with anosmia may not be able to fully taste foods and may lose interest in eating. This can lead to weight loss or malnutrition. Anosmia can also lead to depression because it may impair one's ability to smell or taste pleasurable foods. Platelet-rich plasma (PRP) is an autologous biologic product with anti-inflammatory and neuroprotective effects. This prospective study evaluated the role of PRP on olfactory neuroregeneration in patients with anosmia and compare the results of single and double injections.

54 patients were included in the study who had olfactory loss greater than 6 months in duration, no evidence of sinonasal inflammatory disease, and no improvement with olfactory training and topical steroids. 27 patients received a single intranasal injection of PRP into the mucosa of the olfactory cleft and 27 patients received a double injections with 3 weeks interval between them. The Q-Sticks Test was administered at the beginning of the study and at 1 and 3 months.

All patients reported a subjective improvement of their smell shortly after injection but then stabilized. At 3-month post-treatment, 16 patients improved significantly after single injection and 19 patients improved significantly after double injections. There were no adverse outcomes from intranasal PRP injections.

PRP appears safe for use in the treatment of olfactory loss, and preliminary data suggest possible efficacy, especially for those with persistent loss. Further studies will help determine optimal frequency and duration of use.