Taste Dysfunction and Bell's Palsy: A Scoping Review.

Abstract

Taste dysfunction is a well-recognized but inconsistently reported symptom in Bell's palsy. This scoping review aims to map the literature on the prevalence, mechanisms, and prognostic value of taste dysfunction in Bell's palsy. A comprehensive search strategy was performed using PubMed, Embase, and Web of Science databases. We conducted a scoping review to examine taste dysfunction in patients with idiopathic facial palsy. Searches of PubMed, Embase, and Web of Science were conducted between August 2025 and April 2026 to identify relevant peer-reviewed studies. Data were synthesized descriptively with attention to prevalence, assessment modality, and clinical correlations. Findings have been reported in accordance with PRISMA-ScR guidelines. Nineteen studies met inclusion criteria and were reviewed. Self-reported prevalence of taste dysfunction ranged from 10% to 60%, while psychophysical testing revealed higher rates of subclinical involvement. Several studies reported taste dysfunction in over 70% of patients assessed with taste stimulus testing. Taste dysfunction often preceded facial weakness, suggesting early chorda tympani and greater petrosal nerve involvement. Longitudinal evidence indicates that taste function commonly improves within 6 months, though its association with motor recovery and long-term outcomes remains inconsistently reported. Taste dysfunction is a frequent yet variably reported feature of Bell's palsy. Taste stimulus testing reveals broader facial nerve involvement than patient report alone and may aid early assessment. Standardized, longitudinal studies employing validated psychophysical measures are needed to clarify the prognostic significance of taste deficits and inform comprehensive assessment strategies. NA.