Objective: The objective of the present study was to compare a new type of symptomatic lichenoid reaction, specifically located on the mucosal side of the lips, and associated with microorganisms, with a matched group presenting with reticular oral lichen planus (OLP) of the buccal mucosa.
Patients and methods: The mean age for both groups was 66 years with a predominance of women (62%). The lichenoid reaction group (n = 25) presented with a reticular reaction pattern embracing various degrees of erythema. Patients presenting with OLP had similar lesions confined to the buccal mucosa but not on the mucosal side of the lips.
Results: In both groups, 80% were on any type of medication. However, 56% of the patients with lichenoid reactions medicated with more than three drugs compared with 29% (P < 0.05) in the OLP group. The former group more often used medicaments prescribed for cardiovascular diseases (48%vs 25%). Twenty-two of the patients with lichenoid reactions were treated with chlorhexidine. In 80% of these patients (n = 18), the lesions improved or completely healed, indicating a microbial association.
Conclusion: Lichenoid reactions present on the mucosal side of the lips may be initiated by microbial plaque precipitated on the buccal surfaces of the anterior teeth.