Dysplastic leukoplakia is the equivalent of an actinic keratosis on non-moist skin. Hyperkeratotic skin, when wet, turns white. A patch of white skin on a moist area such as the mouth or vaginal mucosa is suggestive of thickened skin. Skin can become thickened from many causes. This spectrum of causation extends from a hypertrophic response to trauma, to benign human papilloma virus infection, through to dysplastic leukoplakia that is precancerous.
Dysplastic leukoplakia can be secondary to an oncogenic human papilloma virus, or can be secondary to other carcinogens such as, in the case of the oral mucosa, chronic exposure to chewing tobacco. A biopsy is necessary to diagnose dysplastic leukoplakia. If untreated, dysplastic leukoplakia can lead to squamous carcinoma.