Article written for Nuffield Hospital for GPs on: Covid-related loss of smell and taste

As we enter the New Year in a time of flu' and Covid, we caught up with Mr McKay-Davies, an ENT Consultant with a special interest in Ear and Nose surgery at Nuffield Health Tunbridge Wells, to comment on what can be done to manage the often devastating loss of smell that can occur with Covid.

"Along with respiratory symptoms, we are seeing quite a few people suffering from unusual complications of Covid, such as anosmia (total loss of sense of smell - in 10%), sensorineural hearing loss, and aggressive sinus infections, including in children. Once the acute infection has settled, the anosmia can become particularly debilitating and significantly reduce the patient's quality of life. Foods become tasteless, or taste foul, appetite is reduced, and weight loss and depression can ensue. Compared with other forms of post-viral olfactory loss, Covid smell loss is more likely to occur in women, at a younger age (30-40yo), its onset may be sudden, and it may be the only symptom. It does have a better prognosis though, with approximately 90% resolving within a year.

Although we know Covid can cause encephalitis that may contribute to its presentation, and that the majority of symptoms resolve spontaneously, in the first instance the nasal symptoms should be treated as per any other viral infection causing inflammation of the olfactory neuroepithelium. A trial of topical steroids such as higher dose flixonase or betnesol nose drops for a month followed by lower dose fluticasone or mometasone sprays for a few months would be recommended. If the anosmia fails to improve then referral to a rhinologist would be appropriate. They would assess and investigate the patient looking to rule out other causes of smell loss, such as nasal polyps, chronic rhinosinusitis, or sinister causes, such as olfactory neuroblastomas. This may require a flexible nasendoscopy, allergy testing, and CT or MRI scanning. Nasal polyps or chronic rhinosinusitis can be managed surgically following a trial of appropriate medical treatment. For those with persistent Covid-induced anosmia, smell training is recommended. This entails exposing your nose to  a selection of different scented oils twice a day, and changing these odours every twelve weeks. At the moment this appears to be the most effective treatment for those with long-term symptoms (see fifthsense.org.uk, Abscent.org websites). Topical vitamin A, topical sodium citrate, and oral theophylline are under investigation as potential future options. The patient will need to be advised about hazards at home (foods that have gone off, smoke and fire detection), work place adjustments, personal hygiene, and to experiment with enhancement of the non-olfactory aspects of flavour. There are emerging cookbooks that help with this. Finally, don't forget that 10% of those with "idiopathic" hyposmia (reduced sense of smell) without a preceding history of Covid infection, have altered central processing and later develop Parkinson's disease or Alzheimer's. It is therefore suggested for these patients that cardiovascular risk factors are treated and regular neurocognitive assessments are undertaken."

Update: Vitamin D supplements have also recently been shown to improve sense of smell after Covid