The cause is unknown, but it is thought to be caused by intracellular edema of the superficial epithelial cells coupled with retention of superficial parakeratin. Although<unk>  is thought to be a developmental condition, it may be more common and more pronounced in smokers, and becomes less noticeable when smoking is stopped. Smoking cannabis is known to be linked to this condition. It may also develop in areas subjected to repeat subclinical irritation, caused by low grade irritants such as spices, oral debris or tobacco.
Leukoedema
Hypertrichosis
Lipedema
Papilledema
Phimosis
Green nails
Macular edema
Road rash