Efficacy of systemic corticosteroid treatment for anosmia with nasal and paranasal sinus disease.

Systemic administration of corticosteroids was attempted in the treatment of olfactory loss resistant to topical corticosteroid treatment in patients with nasal and paranasal disease and post-upper respiratory infection. Significant efficacy was achieved with a short course of high-dose oral corticosteroids in patients with non-allergic sinus disease. On the other hand, anosmia induced by upper respiratory infection failed to respond to systemic corticosteroid treatment, suggesting permanent damage to the olfactory receptor cell. The underlying mechanism of effectiveness observed in patients with sinus disease may be explained by improvement of the mucosal thickening of the olfactory fissure, leading to the access of an odorant to the olfactory neuroepithelium.