Microbial‐associated oral lichenoid reactions

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.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.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.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.