A seborrheic keratosis is a common, benign, persistent epidermal lesion with a variety of clinical appearances. It is one of the most common benign growths seen on the skin and is often confused with malignancies. Seborrheic keratoses are unusual before age 30. Most people develop at least one seborrheic keratosis in their lifetime. Male and female patients are equally affected. The tendency to develop multiple seborrheic keratoses may be inherited. Seborrheic keratoses are cosmetically bothersome, but may also be subject to irritation and traumatization, depending on location.