Chronic venlafaxine ingestion inducing bluish oral hyperpigmentation with dysgeusia and dysphagia: A case report

BackgroundMedication-induced oral hyperpigmentation represents an adverse drug reaction characterized by variable latency and unclear mechanism. Diagnosis is particularly challenging in older adults due to non-specific symptoms, multiple comorbidities and polypharmacy.Case reportWe present the first documented case of a woman in her 80s experiencing patchy, bluish hyperpigmentation of dorsum of tongue and buccal mucosa with altered taste sensation and swallowing difficulty, in association with chronic venlafaxine ingestion that remained undiagnosed for many years. To establish the current diagnosis, a comprehensive history taking, clinical examination, blood investigations and imaging studies were utilized to rule out the endogenous causes. Following discontinuation of venlafaxine, at 1 month follow-up, there was complete resolution of oral hyperpigmentation together with significant improvement in dysphagia and dysgeusia indicating a probable association with the drug.ConclusionThis report highlights the need for the healthcare professionals to be aware of the medications linked to oral hyperpigmentation to facilitate timely diagnosis, patient reassurance and optimize management.