Leukoedema

Leukoedema is a diffuse, bilateral gray-white or milky opacification of the mucosa, particularly the buccal mucosa (inside of cheeks). It may extend to the labial mucosa and lips along the occlusal line in the canine-molar region.  It may also occur on the mucosa of the larynx or vagina. It is a harmless and very common condition. Because it is so common, it has been argued that it may in fact represent a variation of the normal appearance rather than a disease, but empirical evidence suggests that leukoedema is an acquired condition caused by local irritation. It is found more commonly in black skinned people and tobacco users. The term is derived from the Greek words λευκός leukós, "white" and οἴδημα oídēma, "swelling".

==Epidemiology== Leukoedema is a common condition and multiple studies have demonstrated significant ethnic variation in its prevalence. It occurs in about 58-94% of dark skinned adults, especially those aged 41-45 years and about 50% of dark skinned children. The prevalence in white skinned people is considerably less, but reports range from 43% to 45%, probably varying depending upon the population studied, and the methods used in the study, e.g. examination conditions and the diagnostic criteria. The ethnic variation may be explained by genetic factors or simply because dark skinned people have more melanin in the mucosa, making it appear darker (termed racial or physiologic pigmentation). This darker mucosa may make the edematous changes more noticeable, whereas in the mucosa of people with lighter skin types leukoedema gives a milder presentation. Empirical evidence supports that leukoedema is influenced by chronic local irritation, as high prevalences have been documented among individuals who chew coca leaf–lime and among tobacco users in multiple studies.