Use test with l‐carvone in toothpaste on sensitized individuals

Abstract

AbstractBackgroundThe mint flavour carvone (l‐carvone) is considered a weak contact allergen. However, contact allergy to carvone is more prevalent in patients with oral lichen planus or oral lichenoid lesions (OLP/OLL).ObjectiveOur aim was to investigate how carvone affects sensitized individuals through a use test with toothpaste containing carvone. Non‐flavoured toothpaste served as control.MethodsSubjects were patch tested prior to the use test—14 subjects allergic to carvone (11 with OLP/OLL), 20 subjects with OLP/OLL and 3 healthy controls. The month‐long use test comprised of using toothpaste twice daily. Subjects were examined fortnightly. Clinical signs were assessed with a mucosal scoring system. The subjects' oral health‐related quality of life was measured with the oral health impact profile (OHIP‐49).ResultsLocal reactions to the carvone toothpaste presented as aggravated OLL (7/10) and peri‐oral eczema (2/10) in allergic subjects. They also had significantly higher mucosal and OHIP scores compared with those receiving non‐flavoured toothpaste.ConclusionIn sensitized individuals, oral exposure to carvone gives aggravated oral lesions and/or peri‐oral eczema. The lesions mimic OLP and allergic individuals are therefore at risk of not being assessed with regard to flavour contact allergy.