The prevalence of contact hypersensitivity in patients with oral lichen planus.

Introduction: Oral lichen planus (OLP) is a chronic autoimmune inflammatory disease with an unknown aetiology and a higher prevalence in women. Oral lichenoid lesions both clinically and histologically resemble oral lichen planus and are often associated with contact allergy to dental materials. Aim: To investigate the prevalence of delayed hypersensitivity reactions in patients with OLP and to identify the most common allergens that may exacerbate the disease. Material and methods: Twenty patients diagnosed with OLP and undergoing treatment in the Gerodontology and Oral Pathology Department of the Poznan University of Medical Sciences were enrolled in the study. The subjects underwent a detailed oral examination consisting of anamnesis and a clinical evaluation by a qualified dentist, while an assessment of the skin and skin appendages was carried out by a dermatologist. Patch testing was performed using the Polish Baseline Series and Dental Screening Series. Results: Fifty percent of the examined patients displayed positive patch test reactions. A total of 18 allergic reactions were revealed, but only four appeared during the first test. The most common allergens were found to be nickel, gold, and a fragrance mix. Only 1 patient had a positive reaction to more than three allergens. Conclusions: There seems to be a high contact reaction rate in patients with oral lichen planus, which is not related to contact with synthetic dental materials. However, further investigations on a larger population with the introduction of additional tests administered 7 days after exposure are required to confirm the effects of delayed hypersensitivity reactions on patients with OLP exacerbation.