A study in Sweden showed that 21.5% of<unk> s and 3% of nonsmokers (genetic pigmentation or unknown cause) had lesions that could be classified as an oral melanin pigmentation. A gingival melanin index in 4 degrees was established. Already with a consumption of 1-3 cigarettes a day 9.3% of all 20.333 examined showed a<unk> . Pipe<unk> s had<unk>  in 16.8%. One year after the start of cigarette smoking a clinically visible<unk>  could be seen in 12.3% of women, and 17% among men. In cigarette<unk> s who quit smoking, the number of individuals with<unk>  becomes slowly less frequent after 2–3 months, but can still be seen in a few former<unk> s three years after smoking stop. Although clinically visible genetic melanin pigmentations in the mouth are present in several ethnic groups all over the world, more mucosal areas will be melanin-pigmentet if tobacco products are used.<unk>  is found in India, Italy, Japan, Nigeria, Sweden, Turkey, USA, and several other countries.<unk>  is expected to be found also in other tissue surfaces exposed to tobacco and tobacco<unk>  for instance lips and in skin of the fingers holding the cigarette. Future studies will also show if the use of tobacco exaggerates the pigmentation of skin.
Smoker's melanosis
Riehl melanosis
Becker's nevus
Spitz nevus
Hori's nevus
Drug-induced pigmentation
PUVA keratosis
Diabetic dermadrome