Use test with l‐carvone in toothpaste on sensitized individuals

• Published in: Contact dermatitis Vol. 88; no. 6; pp. 463 - 471
• Main Authors: Kroona, Liv, Ahlgren, Camilla, Dahlin, Jakob, Isaksson, Marléne, Bruze, Magnus
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2023; Wiley Subscription Services, Inc
• Subjects: Allergens; Allergies; Carvone; Clinical Medicine; contact cheilitis; contact stomatitis; Dentifrices; Dentistry; Dermatitis, Allergic Contact - diagnosis; Dermatitis, Allergic Contact - etiology; Eczema; Humans; Klinisk medicin; l-carvone; Lesions; Lichen planus; Lichen Planus, Oral - diagnosis; Medical and Health Sciences; Medicin och hälsovetenskap; Mucosa; mucosal score; Odontologi; Odontology; OHIP-49; Oral hygiene; oral lichen planus; oral lichenoid lesion; Quality of Life; Toothpaste; Toothpastes - adverse effects; use test; OHIP-49; oral lichenoid lesion; l-carvone; toothpaste; use test; oral lichen planus; contact cheilitis; contact stomatitis; mucosal score
• ISSN: 0105-1873; 1600-0536; 1600-0536
• DOI: 10.1111/cod.14302

Background The 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). Objective Our aim was to investigate how carvone affects sensitized individuals through a use test with toothpaste containing carvone. Non‐flavoured toothpaste served as control. Methods Subjects 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). Results Local 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. Conclusion In 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. Allergic contact reactions to l‐carvone in toothpaste present as aggravated oral lichenoid lesions or contact cheilitis, and may mimic oral lichen planus. The intra‐oral use test is a possible method to investigate oral contact stomatitis in a clinical setting.