Caution urged in treating 'steroid-dependent anosmia'

Olfactory training for Olfactory dysfunction in COVID-19: A promising mitigation amidst looming neurocognitive sequelae of the pandemic

Olfactory dysfunction (OD) is a recognized symptom of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is independently associated with neurodegenerative disorders. Moreover, the central nervous system manifestations in patients infected with the coronavirus -2019 (COVID-19) have demonstrated cognitive decline and neuropsychiatric manifestations. Hence, OD in COVID -19 necessitates perusal of its' mechanism and available treatment options to avert possible development of neurocognitive sequelae of the pandemic. The article presents a literature review organized from the published information about olfactory training (OT) for OD during COVID-19. The methodology comprised retrieval of available literature from database searches and subsequent scrutinization of relevant information. Inferentially, Injury to the sustentacular cells, possessing angiotensin-converting enzyme 2 (ACE-2) receptors, is an important mechanism causing OD in COVID-19. OD may be prolonged in severe cases of anosmia predisposing to neurodegenerative and cognitive impairment in COVID-19 infection. OT demonstrates an effective treatment for OD based on human and animal-derived evidence through recent studies. It curtails the progression of OD, besides inducing neural rearrangement and changes in functional connectivity in patients receiving OT. Additionally, contemporary reports support that the administration of OT for COVID-induced anosmia is effective and encompasses no significant adverse effects. The present review highlights the prominence of olfactory training as a recommended intervention for OD in COVID-19. This review can guide the clinicians in curbing neurological repercussions of COVID besides enhancing cognitive rehabilitation through olfactory training.

Treatments for smell and taste disorders: A critical review

A key concern of both the patient and physician is whether treatment is available that will eliminate or quell a given chemosensory disturbance. In cases where obvious oral, nasal, or intracranial pathology is involved, rational straightforward approaches to treatment are often available. In cases where damage to the sensory pathways is secondary to chronic inflammatory disease, trauma, viral invasion, toxic exposure, or unknown causes, the direction for therapy is more challenging. Indeed, many chemosensory disorders, if present for any period of time, cannot be reversed, while others spontaneously remit without any therapeutic intervention. This review assesses the strengths and weaknesses of more than two dozen approaches to treatment that have been suggested for a wide range of taste and smell disorders.

Treatment of chronic rhinosinusitis with pressure-pulsed corticosteroid inhalation

Chronic rhinosinusitis may cause olfactory dysfunction and affects quality of life in patients. In a prospective study we investigated the effect of topical application of corticosteroids through pressure-pulsed inhalation as treatment option of chronic rhinosinusitis with olfactory disorder. Patients with sinonasal olfactory disorder according to the European Position Paper on Rhinosinusitis and Nasal Polyps (EP3OS) were allocated to the new nasal inhalation therapy or a systemic corticosteroid therapy, each receiving a corticosteroid course of 12 days. 18 patients received topical corticosteroid pressure-pulsed inhalation (AMSA, Schumacher, Dausenau) and 15 systemic corticosteroid. Olfactory function was measured before and after treatment using the Threshold Discrimination Identification score (TDI score) and visual analogue scales. Lund Mackay score (LMS) was measured before starting treatment. Olfactory function (OF) increased from 17.5 ± 6.4 to 21 ± 7.9 TDI points (p < 0.0005) after 2 months. OF decreased again to 19.5 ± 6.0 after 6 months (p = 0.007). OF increased from 17.0 ± 8.9 to 22.0 ± 9.5 points (p = 0.002) with systemic treatment after 2 months. In the follow-up period of 6 months, the mean TDI score dropped to 20.0 ± 9.2 points (p = 0.01). There was no correlation between LMS and TDI. Treatment of chronic rhinosinusitis with pressure-pulsed inhalation was demonstrated to be effective. Multicenter investigations with large participant numbers are needed.

Chronic sinusitis and olfactory dysfunction

Chronic rhinosinusitis encompasses a group of disorders characterized by inflammation of the mucosa of the nose and paranasal sinuses of at least 12 weeks' duration. In addition to nasal obstruction and discharge, chronic sinusitis is a common cause of olfactory dysfunction. Smell loss can result in problems including safety concerns, hygiene matters, appetite disorders, and changes in emotional and sexual behavior. Although smell loss related to sinonasal disease is probably the most treatable form of olfactory dysfunction and treatment can improve olfactory sensation in the setting of sinusitis, most studies show that the effects are usually transient and incomplete.

Placebo-controlled, randomized, double-blind study evaluating the efficacy of fluticasone propionate nasal spray for the treatment of patients with hyposmia/anosmia

OBJECTIVE

To compare the effect on olfaction of topical glucocorticoid treatment versus placebo given for an extended period in addition to oral short-term glucocorticoids in patients with anosmia/hyposmia.

MATERIAL AND METHODS

This was a randomized, double-blind, placebo-controlled study. The criterion for inclusion in the blinded phase was an improvement of at least 2 steps in the butanol odor threshold test following open treatment for 10 days with oral and nasal corticosteroids. Forty patients were included: 20 were randomized to treatment with fluticasone propionate, 10 to placebo and 10 others as controls. The topical treatment was continued for 6 months.

RESULTS

The 3 groups showed similar improvements in their sense of smell after the initial 10-day treatment with combined oral and nasal corticosteroids. Patients who continued the local treatment maintained the same level of improvement throughout the study, whether or not they had been given nasal corticosteroids or placebo. We found no significant differences between the treatment groups.

CONCLUSIONS

In patients with anosmia/hyposmia partly caused by local inflammation, no further improvement in the olfactory threshold is achieved by continuing with a topical intranasal glucocorticoid after an initial combined topical and systemic glucocorticoid treatment.

A randomized controlled study evaluating medical treatment versus surgical treatment in addition to medical treatment of nasal polyposis

BACKGROUND

Controlled prospective studies are needed to determine whether surgical treatment in fact has an effect additive to that of medical treatment of nasal polyposis.

OBJECTIVE

We sought to compare the effect of medical treatment versus combined surgical and medical treatment on olfaction, polyp score, and symptoms in nasal polyposis.

METHODS

Thirty-two patients with nasal polyposis and symmetrical nasal airways were randomized to unilateral endoscopic sinus surgery after pretreatment with oral prednisolone for 10 days and local nasal budesonide bilaterally for 1 month. Postoperatively, patients were given local nasal steroids (budesonide). Patients were evaluated with nasal endoscopy, symptom scores, and olfactory thresholds. They were followed for 12 months.

RESULTS

The sense of smell was improved by the combination of local and oral steroids. Surgery had no additional effect. Symptom scores improved significantly with medical treatment alone, but surgery had additional beneficial effects on nasal obstruction and secretion. After surgery, the polyp score decreased significantly on the operated side but remained the same on the unoperated side. Twenty-five percent of the patients were willing to undergo an operation also on the unoperated side at the end of the study.

CONCLUSIONS

Medical treatment seems to be sufficient to treat most symptoms of nasal polyposis. When hyposmia is the primary symptom, no additional benefit seems to be gained from surgical treatment. If nasal obstruction is the main problem after steroid treatment, surgical treatment is indicated. Selection of those who will benefit from surgery should be based on the patient's symptoms and not on the examiner's polyp score.

Interleukin-1 beta, interleukin-5, interleukin-6, interleukin-8, and tumor necrosis factor-alpha in chronic sinusitis: response to systemic corticosteroids

Recently, the role of various cytokines in the pathogenesis of chronic rhinosinusitis has come under investigation. Various studies have reported increased levels of interleukin-3, interleukin-4, interleukin-5, interleukin-13, and granulocyte macrophage-colony stimulating factor in the sinonasal mucosa of patients with chronic rhinosinusitis. The present study investigated the levels of pro-inflammatory cytokines, including interleukin-1 beta (IL-1 beta), interleukin-5 (IL-5), interleukin-6 (IL-6) interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha), in the sinonasal mucosa of patients with chronic rhinosinusitis, and evaluated the response of these cytokines to oral corticosteroids. Chronic rhinosinusitis subjects (n = 15) and control subjects (n = 9) underwent nasal endoscopy and biopsy of the sinonasal mucosa. Chronic rhinosinusitis subjects were subsequently treated with a 10-day tapering dose of prednisone followed by a second sinonasal endoscopic exam and biopsy. Mucosal biopsy specimens were immunostained for IL-1 beta, IL-5, IL-6, IL-8, and TNF-a. In chronic rhinosinusitis subjects, mucosal levels of IL-1 beta, IL-6, IL-8, and TNF-alpha were significantly elevated when compared with control subjects, and levels of IL-5 demonstrated a strong trend toward elevation. In posttreatment chronic rhinosinusitis subjects, levels of IL-6 were significantly decreased when compared with pretreatment levels, and TNF-alpha levels demonstrated a significant trend toward reduction. These findings support the hypothesis that the inflammatory response in chronic rhinosinusitis is associated with elevated levels of pro-inflammatory cytokines, and suggest that oral corticosteroids may exert a beneficial effect by significantly reducing the levels of IL-6 and TNF-alpha.

Disorders in taste and smell

Although many conditions and medications have been associated with chemosensory disturbances, data from major chemosensory clinical research centers support three major disorders as being causative: nasal and paranasal sinus disease (21%), post-upper respiratory tract viral infection (19%), and head trauma (14%). Despite extensive evaluation, 22% of patients do not demonstrate identifiable causation.