Work

Immediate impact of a short course of systemic corticosteroid on olfactory dysfunction, parosmia, and phantosmia

Year: 2025

Type: article

Abstract: Systemic corticosteroids effectively treat conductive olfactory dysfunction from chronic rhinosinusitis. However, more evidence is needed for their effects on smell loss from other causes. This study measured the impact of a 7-day prednisolone course on quantitative and qualitative olfactory dysfunction in patients with postinfectious, post-trauma, and idiopathic smell disability. Data from 120 patients with olfactory dysfunction were analyzed. Scores on the University of Pennsylvania Smell Identification Test (UPSIT®), as well as ratings of self-perceived smell ability and complaints of parosmia and phantosmia, were determined before and immediately after the 7 days of treatment with 40 mg of oral prednisolone. Ten patients were controls. Twenty-six patients (23.6 %) experienced a clinically significant improvement of at least 4 UPSIT® points following prednisolone treatment, compared to only 10 % of the control group. Thirteen (24.5 %) of the 53 patients who had persistent olfactory dysfunction (≥6 months) had a clinically significant improvement after the steroid treatment. Nine patients with parosmia (18.4 %) improved this symptom after the treatment, while 5 (27.8 %) of those with phantosmia reported relief. Patients with worse function in the first visit exhibited greater recovery. COVID-19 patients generally presented earlier to medical consultation and had the highest chance of having parosmia (63.4 %) and phantosmia (22.9 %). This study supports the concept that a short course of prednisolone may be efficacious in cases of non-conductive quantitative and qualitative olfactory dysfunction. Additional clinical trials are needed to exclude its placebo beneficial effect on the qualitative complaints of parosmia and phantosmia. Level of evidence: 3. • There are few medications with high efficacy for non-conductive smell disturbances and even fewer for qualitative symptoms such as parosmia and phantosmia. • The results of this study demonstrate that a short course of prednisolone may be efficacious in quantitative and qualitative olfactory dysfunction. • Patients with worse initial smell capacity exhibited more remarkable recovery using this oral steroid. • A more prolonged onset (≥ six months) was not impeditive to an improvement. • 18.4% of patients with parosmia improved this symptom, and more than 25% of those with phantosmia reported relief.

Source: American Journal of Otolaryngology

DOI: 10.1016/j.amjoto.2025.104760