Olfactory dysfunction is a prevalent disorder that affects up to 20% of the general population and has significant effects on a person's quality of life as well as increased morbidity and mortality (Croy I et al., 2014;Nordin S et al
.,2008). Anosmia is the inability to perceive the odor or a lack of functioning olfaction; it may be temporary or permanent. Organic anosmia is loss of smell due to nasal obstruction caused by sinonasal diseases (as nasal polyps, tumors, postoperative) preventing odorant molecules from reaching olfactory mucosa. Functional anosmia affects up to 5% of the general population and 10% of those older than 65 . Functional anosmia is due to damage of peripheral olfactory area causing permanent loss of smell as post-traumatic, post viral infection. . 20% of individuals aged 20 to 90 years have impaired olfactory Function . The etiology of olfactory dysfunction is quite varied, including post viral posttraumatic, and idiopathic loss of smell. Unfortunately, with these etiologies, the likelihood of spontaneous recovery is generally poor with only approximately one-third of people regaining function and the duration of loss negatively correlating with recovery rate . Treatment for olfactory dysfunction is also limited. Best evidence studies recommend olfactory training and topical steroid nasal irrigations as potential therapeutics, yet both have limited efficacy . PRP is an autologous materials known to have anti-inflammatory and proregenerative properties including up regulation of growth factors including transforming growth factor, vascular endothelial growth factor, epidermal growth factor, and insulin-like growth factor. It has been used as a safe therapy effective in treating inflammation, wound healing, and peripheral neuropathies in other clinical settings. In particular, PRP has been shown to promote axon regeneration and neuroregeneration .
