<unk>  is very common, with an estimated 14% of dermatology visits related to<unk> s. It is seen more often in fair-skinned individuals, and rates vary with geographical location and age. Other factors such as exposure to ultraviolet (UV) radiation, certain phenotypic features, and immunosuppression can also contribute to the development of<unk> s. Men are more likely to develop<unk>  than women, and the risk of developing<unk>  lesions increases with age. These findings have been observed in multiple studies, with numbers from one study suggesting that approximately 5% of women ages 20–29 develop<unk>  compared to 68% of women ages 60–69, and 10% of men ages 20–29 develop<unk>  compared to 79% of men ages 60–69. Geography seems to play a role in the sense that individuals living in locations where they are exposed to more UV radiation throughout their lifetime have a significantly higher risk of developing<unk> . Much of the literature on<unk>  comes from Australia, where the prevalence of<unk>  is estimated at 40–50% in adults over 40, as compared to the United States and Europe, where prevalence is estimated at under 11–38% in adults. One study found that those who immigrated to Australia after age 20 had fewer<unk> s than native Australians in all age groups.
Actinic keratosis
Squamous cell skin cancer
Hydrocarbon keratosis
Arsenical keratosis
Reactional keratosis
Seborrheic keratosis
Smokeless tobacco keratosis
PUVA keratosis