A multicenter study of oral lichen planus in Thai patients

Aim: Oral lichen planus is an oral mucosal disease that affects middle-aged patients. The characteristics of oral lichen planus in Thai patients from a multi-center were studied. Methods: Data of 533 patients from the oral medicine clinics at Chulalongkorn and Mahidol (central Thailand), Chiang Mai (northern Thailand), and Khon Kaen (northeastern Thailand) universities during 2002-2007 were analyzed. The diagnosis of patients with oral lichen planus was clinically and/or histopathologically confirmed. Results: There was a greater number of female patients than males (4: 1). There were significant differences in age, sex, and some systemic diseases among the oral lichen planus patients from the three centers. Burning sensation was the most common symptom (72.9%), followed by pain (26.5%), roughness (6.4%), and then no other symptoms (7.9%). The most common site of lesions was found at the buccal mucosa (87.1%). Atrophic oral lichen planus was common in Thai patients. There were significant differences in the types of oral lichen planus, including reticular, atrophic, and ulcerative oral lichen planus among these patients from the three centers (P = 0.000). Nine cases (1.7%) showed dysplasia, but one case (0.2%) developed squamous cell carcinoma. Conclusion: Patients with oral lichen planus from the central, northern, and northeastern parts of Thailand presented with distinct characteristics. The malignant transformation of oral lichen planus was low in Thai patients.