The significance of oral and systemic factors in Australian and Croatian patients with oral lichen planus.

Oral lichen planus (OLP) is an immunologically T cell-mediated disease caused by an unknown stimulus. Despite intensive investigation its pathogenesis still remains unknown. A few possible associations between OLP and certain diseases such as thyroid and malignant diseases as well as specific medication intake have been proposed in the literature with inconsistent findings. We aimed to investigate the profile of 163 Australian and 163 Croatian OLP patients with special regard to their systemic diseases, medication intake (with special regard to the drugs that metabolize through Cytochrome P450), OLP type and localization, as well as involvement of other body surfaces with lichen. We did not find any statistical significance with regard to the OLP presence and thyroid and malignant diseases. As expected, the reticular type of OLP was most prevalent, as well as involvement of the both buccal mucosas. There was no significant association with other oral diseases such as labial herpes. Simultaneous involvement of other body surfaces in patients with OLP does not seem to be prevalent. None of the medical conditions which were investigated had significant correlation with OLP neither in Australian nor in Croatian patients with OLP. Furthermore, the use of drugs which metabolize through Cytochrome P450 (CYP450) was not significantly correlated with OLP in either studied population. Therefore, we conclude that patients with OLP are not to be routinely screened for any systemic conditions.