Randomized Clinical Trial of Intranasal Injection of Platelet-Rich Plasma

Persistent smell disorders are a major health issue worldwide. They are increasing in prevalence, and can greatly impact both quality of life as well as actual mortality rates. As the ability to smell also has a major impact on the ability to taste, losing this sense often leads to loss of enjoyment of food and drink. It can also lead to anxiety and depression. Many people with hyposmia, or smell loss, also experience parosmia, a condition where smells and tastes are distorted. Current treatments for parosmia are limited and not effective. Platelet-rich plasma (PRP) is a substance made from the patient's own blood that helps with inflammation and wound healing when injected into an area of the body that needs to regenerate. Based on a prior study by Professor Zara Patel showing that PRP can help people with smell loss, we believe PRP could also be a new and effective treatment for parosmia. The aim of this project is to evaluate if PRP injections into the olfactory cleft within the nose can also help people with parosmia. The main measures of success will be changes in smell test scores and subjective changes in smell distortion after 3 months.