Epidemiology
Presence and frequency increase with age: almost all elderly patients have some. An Australian study found 100% of the over-50-year-olds in their sample had at least one seborrhoeic keratosis (median number of 23 keratoses in the 51-75 year range, and 69 keratoses in the over-75-year-olds).
Onset is usually in middle age although a common finding in younger patients - found in 12% of 15-year-olds to 25-year-olds making the term "senile keratosis" redundant.
No difference in prevalence exists between genders. There is less prevalence in people with darker skin.
Read more about this topic: Seborrheic Keratosis