Having played a pivotal role in identifying the high rate of anosmia associated with COVID-19, much of my research and clinical practice since the pandemic has focused on following the outcomes of patients suffering with persistent smell and taste disorders and striving to find treatment options to offer them. As an author of the International Consensus on Olfaction, led by Prof Zara Patel, and the European Position Paper on Olfactory Disorders, I am keenly aware of the paucity of interventions available to my patients with post-viral loss, with the exception of smell training and dietary supplements.
Many treatments that have previously been recommended in the treatment of post-viral smell loss had not been evaluated in high quality placebo-controlled trials, instead recommendations were made based on often poor quality, retrospective studies with small numbers of patients and no control arms. A silver lining of COVID has been the ability to better evaluate these treatments. Once the relatively high rates of spontaneous recovery have been controlled for, several treatments previously thought to be helpful have been shown to be no better than placebo.
In contrast, Prof Patel, Prof Yan and their team demonstrated significantly higher rates of improvement (57.1%) in patients receiving 3 injections of PRP compared to a placebo (saline) injection (8.3%), in a double-blinded, randomised controlled trial, considered to be the highest level of evidence. However, when these results were first published, I was hesitant to offer treatment, as I wanted to be confident that any benefit seen in the first three months was maintained overtime. The long-term outcomes, first presented at the American Rhinological Society are more compelling – there is an even greater difference between the 2 arms in terms of the proportion of patients who have improved (87.5% vs. 31.2%) and the degree of improvement is greater. Based on these results, I feel it is important to ensure that patients in the UK are able to access these treatments. I have set up a service within my private practice and am in the process of seeking approvals required to offer this in the NHS. All patients will be assessed with formal smell testing before and after treatment, and outcomes will be measured to add to the body of evidence.
The availability of PRP as a treatment option is something that should be celebrated by those who aim to support patients with loss of sense of smell. I would hope that other ENT specialist will soon be able to offer this treatment. Fifth Sense is right to be cautious – certainly the published studies highlight that PRP will not help all patients with post-viral smell loss, and further studies are required before we can make recommendations for use in patients with smell loss from other causes.
NICE approval does not reflect clinical effectiveness, but instead the willingness of the NHS to pay for treatments. Sadly, despite campaigning for many years, on behalf of the British Rhinological Society and as one of the researchers involved in trials to develop biological treatments for nasal polyps, and condition associated with high rates of anosmia, the UK now remains one of the few countries in Europe where there is no reimbursement for use of treatments such as Dupixent. It became clear, when acting as the expert advisor to the NICE appraisal process, that the NHS does not value the sense of smell or understand the impact that its loss has on patients. Nonetheless, I remain hopeful that both PRP injections for the treatment of post-viral loss and biologics for the treatment of smell loss caused by nasal polyps will become available within the near future, and I will continue to strive to achieve this.
Professor Claire Hopkins FRCS is a British Ear, Nose & Throat (ENT) surgeon at Guy’s Hospital and Professor of Rhinology at King’s College London. During the COVID-19 pandemic, Hopkins successfully campaigned to have anosmia recognised as a symptom of COVID-19 in the United Kingdom
