A seborrheic keratosis is a lesion on the skin. The lesions are caused by the cumulative effects of long-term exposure to ultra violet (UV) light. The condition often affects people who spend extended periods outdoors. While it is also common in the elderly, some ethnic groups may also be more susceptible to developing seborrheic keratosis at a young age. Seborrheic keratoses are noncancerous skin growths with a low chance of turning into skin cancer.