Post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation is dark pigmentation of the mucosa of the oral cavity, which can appear following inflammation (e.g. inflammatory disease as oral Lichen Planus); it is due to an abnormal stimulation of melanocytes.  It often presents on the lips and the buccal mucosa with irregular margins, differentiated color and is of variable dimensions. Post-inflammatory hyperpigmentation is not pathologically significant; it is necessary to differentiate a diagnosis of post-inflammatory hyperpigmentation from that of other oral pigmentation.