Whitening toothpaste-induced oral mucosal hypersensitivity reaction resembling oral lichenoid reaction: a clinically diagnosed case report

This case report describes an instance of oral mucosal hypersensitive reaction resembling oral lichenoid reaction (OLR) induced by the use of a whitening toothpaste in a 28-year-old female patient presenting with extensive white hypersensitive reaction on the oral mucosa. The clinical features resembled an oral mucosal hypersensitivity reaction with lichenoid morphology. A detailed history revealed a clear temporal association between the onset of the reaction and the use of whitening toothpaste. Symptoms rapidly improved following discontinuation of the product, and a positive rechallenge test further confirmed the causal relationship. In conjunction with a review of the literature, the potential pathogenic mechanisms of abrasive agents (e.g., calcium carbonate), chemical agents [e.g., hydrogen peroxide (HP), sodium lauryl sulfate (SLS)], and other additives in whitening toothpaste are discussed. This case documents the first confirmed association between whitening toothpaste and an oral mucosal hypersensitivity reaction with lichenoid morphology, highlighting the importance of differentiating hypersensitivity mechanisms in lichenoid-like presentations.